View source for radius

{{also|Radius|RADIUS|radíus}}
==English==
[[File:Radie.png|thumb|The radius of a circle, shown in red]]

===Etymology===
{{bor+|en|la|radius||ray}}. {{doublet|en|ray}}.

===Pronunciation===
* {{enPR|rā'-dē-əs}}, {{IPA|en|/ˈɹeɪ.di.əs/}}
* {{audio|en|en-us-radius.ogg|a=US}}
* {{rhymes|en|eɪdiəs|s=3}}
* {{hyphenation|en|ra|di|us}}

===Noun===
{{en-noun|radii|+}}

# {{lb|en|anatomy}} The long [[bone]] in the [[forearm]], on the side of the [[thumb]].
#* {{quote-book|en|title=The Muscular Motions of the Human Body|passage=It is also obvious, and proved by experiment, that the rotatory motions observed in the hand proceed from the rotatory motions of the '''radius'''.|year=1808|author=w:John Barclay|page=396|url=https://www.google.ca/books/edition/The_Muscular_Motions_of_the_Human_Body/Geo-AAAAcAAJ?hl=en&gbpv=0|oclc=4171281}}
# {{lb|en|zoology}} The lighter bone (or fused portion of bone) in the forelimb of an animal.
# {{lb|en|entomology}} One of the major veins of the insect wing, between the [[subcosta]] and the [[media]]; the vein running along the [[costal]] edge of the [[discal]] cell.
# {{lb|en|geometry}} A line segment between any point of a [[circle]] or sphere and its center.
#: {{ux|en|Fatima claims to have visited all the bars within a five-mile '''radius''' of her Manhattan apartment.}}
#* {{quote-book|en|year=1994|translator=Miles Reid|author=Viacheslav V. Nikulin; Igor R. Shafarevich|title=Geometries and Groups|pageurl=https://books.google.com.au/books?id=K-n1CAAAQBAJ&pg=PA194&dq=%22spherical+geometries%22&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwipoZXR9LvuAhUDyzgGHS1ODIoQ6AEwA3oECEwQAg#v=onepage&q=%22spherical%20geometries%22&f=false|page=194|publisher=Springer
|passage=We start with spherical geometries. The two geometries on spheres of '''radiuses''' R<sub>1</sub> and R<sub>2</sub> are obviously identical if R<sub>1</sub> = R<sub>2</sub>; moreover, the converse also holds.}}
#* {{quote-journal|en|year=2016|date=|author=Jubee Sohn; Ho Seong Hwang; Margaret J. Geller; Antonaldo Diaferio; Kenneth J. Rines; Myung Gyoon Lee; Gwang-Ho Lee|title=Compact Groups of Galaxies with Complete Spectroscopic Redshifts in the Local Universe|journal=JKAS|url=http://arxiv.org/abs/1601.02646|doi=|volume=2015|issue=|pages=
|passage=The velocity dispersions of early- and late-type galaxies in compact groups change little with groupcentric '''radius'''; the '''radii''' sampled are less than <math>100 ~h^{-1}</math> kpc, smaller than the '''radii''' typically sampled by members of massive clusters of galaxies. }}
# {{lb|en|geometry}} The length of this line segment.
#* {{quote-book|en|year=1998|author=Dieter Schuocker|title=Handbook of the Eurolaser Academy|publisher=Springer Science & Business Media|isbn=9780412819100|page=51
|passage=This contribution reduces with increasing distance p from the emitting surface element dA, due to conservation of energy, as the wave energy distributed across the spherical wave front remains constant, while the '''radius''' increases during&nbsp;...}}
# Anything resembling a radius, such as the [[spoke]] of a [[wheel]], the movable arm of a [[sextant]], or one of the radiating lines of a spider's web.
#* {{quote-book|en|title=Animadversions on the Firſt Part of the Machina Coelestis of the {{...}} Aſtronomer Johannes Hevelius {{...}}|passage={{...}} I can do more with a Quadrant, Sextant or Octant, of 1 foot '''Radius''', furniſhed with Teleſcopical Sights and Screws, then {{sic}} can poſſibly be done with any other Inſtrument, furniſhed only with Common Sights, though 10, 20, 30, nay threeſcore foot '''Radius'''; {{...}}|year=1674|author=w:Robert Hooke|page=43|url=https://www.google.ca/books/edition/Animadversions_on_the_First_Part_of_the/KAtPAAAAcAAJ?hl=en&gbpv=0}}
# {{lb|en|graph theory}} The [[minimum]] [[eccentricity]] of any [[vertex]], for a given [[graph]].

====Synonyms====
* {{sense|vein of insect wing}} {{l|en|R}}

====Derived terms====
{{der3|en|radius arm|radius bar|radius rod|Bohr radius|Debye radius|hydraulic radius|potato radius|radius of action|radius of convergence|radius of curvature|radius of gyration|radius vector|Schwarzschild radius|sight radius| van der Waals radius}}

====Related terms====
* {{l|en|radial}}
* {{l|en|radiad}}
* {{l|en|radiate}}, {{l|en|radiation}}

====Translations====
{{trans-top|bone (human)}}
* Arabic: {{t|ar|كُعْبُرَة|f}}
*: Egyptian Arabic: {{t|arz|كعبرة|f|tr=kuʕbura|sc=Arab}}
* Armenian: {{t+|hy|ճաճանչոսկր}}
* Bulgarian: {{t|bg|[[лъчев]]а [[кост]]|f|sc=Cyrl}}
* Catalan: {{t+|ca|radi|m}}
* Chinese:
*: Mandarin: {{t+|cmn|橈骨|tr=ráogǔ}}
* Czech: {{t|cs|vřetenní kost|f}}
* Dutch: {{t+|nl|spaakbeen|n}}, {{t+|nl|radius|m}}
* Esperanto: {{t|eo|radiuso}}
* Finnish: {{t+|fi|värttinäluu}}
* French: {{t+|fr|radius|m}}
* German: {{t+|de|Speiche|f}}, {{t+|de|Radius|m}}
* Greek: {{t+|el|κερκίδα|f}}
* Hungarian: {{t+|hu|orsócsont}}
* Ido: {{t+|io|radiuso}}
* Irish: {{t|ga|gaghéag|f}}
* Italian: {{t+|it|radio|m}}
* Japanese: {{t+|ja|橈骨|tr=とうこつ, tōkotsu|sc=Jpan}}
* Kalmyk: {{t|xal|шу}}
* Kannada: {{t+|kn|ಮುಂಗೈ ಮೂಳೆ}}
* Kazakh: {{t|kk|кәрі жілік}}
* Korean: {{t+|ko|노뼈}}, {{t|ko|요골}}
* Kurdish:
*: Northern Kurdish: {{t|kmr|kewere}}
* Malay: {{t+|ms|radius}}
* Maori: {{t|mi|āpiti}}
* Mongolian:
*: Cyrillic: {{t+|mn|шуу}}, {{t|mn|шуу яс}} {{qual|China}}
* Old English: {{t|ang|hresel}}
* Polish: {{t|pl|kość promieniowa|f-p}}
* Portuguese: {{t+|pt|rádio|m}}
* Romanian: {{t+|ro|radius|n}}
* Russian: {{t|ru|лучева́я кость|f}}
* Serbo-Croatian: {{t+|sh|žbica|f}}, {{t|sh|palčana kost|f}}
* Spanish: {{t+|es|radio|m}}
* Telugu: {{t+|te|రత్ని}}
* Ukrainian: {{t|uk|променева кістка|f}}
* Vietnamese: {{t|vi|xương quay}}
* Volapük: {{t|vo|radiut}}
* Welsh: {{t|cy|gwäell y fraich|f}}
{{trans-bottom}}

{{trans-top|line segment}}
* Afrikaans: {{t|af|radius}}
* Arabic: {{t|ar|نُصْف قُطْر|m}}, {{t|ar|شُعَاع|m}}
* Armenian: {{t+|hy|շառավիղ}}
* Basque: {{t|eu|erradio}}
* Belarusian: {{t|be|ра́дыус|m}}
* Breton: {{t+|br|skin|m}}
* Bulgarian: {{t|bg|ра́диус|m}}
* Burmese: {{t+|my|အချင်းဝက်}}
* Catalan: {{t+|ca|radi|m}}
* Cebuano: {{t|ceb|tungatid}}
* Chinese:
*: Mandarin: {{t+|cmn|半徑|tr=bànjìng}}
* Czech: {{t+|cs|poloměr|m}}
* Danish: {{t+|da|radius}}
* Dutch: {{t+|nl|straal|f}}
* Esperanto: {{t|eo|radiuso}}
* Estonian: {{t+|et|raadius}}
* Faroese: {{t|fo|radius|m}}
* Finnish: {{t+|fi|säde}}
* French: {{t+|fr|rayon|m}}
* Friulian: {{t|fur|rai|m}}
* Galician: {{t+|gl|raio|m}}
* Georgian: {{t|ka|რადიუსი}}
* German: {{t+|de|Radius|m}}, {{t+|de|Halbmesser|m}} {{q|rare}}
* Greek: {{t+|el|ακτίνα|f}}
* Gujarati: {{t+|gu|ત્રિજ્યા|f}}
* Hebrew: {{t+|he|רַדְיוּס|m|tr=rádyus}}
* Hindi: {{t+|hi|त्रिज्या|f}}
* Hungarian: {{t+|hu|sugár}}
* Icelandic: {{t+|is|radíus|m}}, {{t+|is|geisli|m}}
* Ido: {{t+|io|radiuso}}
* Indonesian: {{t+|id|radius}}
* Irish: {{t|ga|ga|m}}
* Italian: {{t+|it|raggio}}
* Japanese: {{t+|ja|半径|tr=はんけい, hankei|sc=Jpan}}
* Kannada: {{t+|kn|ತ್ರಿಜ್ಯ}}
* Kazakh: {{t|kk|радиус}}
* Korean: {{t+|ko|반지름}}, {{t+|ko|반경}}
* Kurdish:
*: Northern Kurdish: {{t|kmr|nîvtîre}}
* Latvian: {{t+|lv|rādiuss|m}}
* Lithuanian: {{t|lt|spindulys|m}}
* Macedonian: {{t|mk|радиус|m}}, {{t|mk|полупре́чник|m|lit=semidiameter}}
* Malay: {{t+|ms|jejari}}
* Maori: {{t|mi|pūtoro}}
* Marathi: {{t|mr|त्रिज्या|f}}
* Mongolian: {{t+|mn|радиус}}
* Norwegian:
*: Bokmål: {{t+|nb|radius|m}}
*: Nynorsk: {{t|nn|radius|m}}
* Persian: {{t+|fa|شعاع|tr=šo'â'}}
* Polish: {{t+|pl|promień|m}}
* Portuguese: {{t+|pt|raio|m}}
* Punjabi: {{t|pa|ਰੇਡੀਅਸ}}
* Romanian: {{t+|ro|rază|f}}
* Russian: {{t+|ru|ра́диус|m}}
* Scottish Gaelic: {{t|gd|spòg|f}}
* Serbo-Croatian:
*: Cyrillic: {{t|sh|полупречник|m|sc=Cyrl}}
*: Roman: {{t|sh|poluprečnik|m}}
* Slovak: {{t|sk|polomer|m}}
* Slovene: {{t+|sl|polmer|m}}
* Spanish: {{t+|es|radio|m}}
* Swedish: {{t+|sv|radie}}
* Tagalog: {{t|tl|lihit}}
* Telugu: {{t|te|వ్యాసార్థము}}
* Thai: {{t+|th|รัศมี}}
* Turkish: {{t+|tr|yarıçap}}
* Ukrainian: {{t+|uk|ра́діус|m}}
* Urdu: {{t|ur|رداس|m|tr=radās}}, {{t|ur|نصف قطر|tr=nisf-qutr}}
* Vietnamese: {{t+|vi|bán kính}}
* Volapük: {{t|vo|raid}}
* Welsh: {{t|cy|radiws|m}}
* Yiddish: {{t|yi|ראַדיוס|m}}
{{trans-bottom}}

{{trans-top|length of this line segment}}
* Armenian: {{t+|hy|շառավիղ}}
* Belarusian: {{t|be|ра́дыус|m}}
* Bulgarian: {{t|bg|ра́диус|m}}
* Catalan: {{t+|ca|radi|m}}
* Chinese:
*: Mandarin: {{t+|cmn|半徑|tr=bànjìng}}
* Czech: {{t+|cs|poloměr|m}}
* Dutch: {{t+|nl|straal|f}}
* Finnish: {{t+|fi|säde}}
* French: {{t+|fr|rayon|m}}
* German: {{t+|de|Radius|m}}, {{t+|de|Halbmesser|m}} {{q|rare}}
* Hindi: {{t+|hi|त्रिज्या |f}}
* Hungarian: {{t+|hu|sugár}}
* Icelandic: {{t+|is|radíus|m}}, {{t+|is|geisli|m}}
* Irish: {{t|ga|ga|m}}
* Italian: {{t+|it|raggio|m}}
* Japanese: {{t+|ja|半径|tr=はんけい, hankei|sc=Jpan}}
* Korean: {{t+|ko|반지름}}
* Macedonian: {{t|mk|радиус|m}}, {{t|mk|полупре́чник|m}}
* Malay: {{t+|ms|jejari}}
* Marathi: {{t|mr|त्रिज्या|f}}
* Norwegian:
*: Bokmål: {{t+|nb|radius|m}}
*: Nynorsk: {{t|nn|radius|m}}
* Polish: {{t+|pl|promień|m}}
* Portuguese: {{t+|pt|raio|m}}
* Romanian: {{t+|ro|rază|f}}
* Russian: {{t+|ru|ра́диус|m}}
* Serbo-Croatian:
*: Cyrillic: {{t|sh|полупречник|m|sc=Cyrl}}
*: Roman: {{t|sh|poluprečnik|m}}, {{t+|sh|polumjer|m}} {{qualifier|Croatia}}
* Slovene: {{t+|sl|polmer|m}}
* Spanish: {{t+|es|radio|m}}
* Swedish: {{t+|sv|radie}}
* Ukrainian: {{t+|uk|ра́діус|m}}
* Volapük: {{t|vo|raid}}
* Welsh: {{t|cy|radiws|m}}
{{trans-bottom}}

===Verb===
{{en-verb}}

# {{lb|en|transitive}} To give a rounded edge to.
#* {{quote-book|en|year=2014|author=Anil Mital; Anoop Desai; Anand Subramanian|title=Product Development|page=358
|passage=A comfortable grip is ensured by smoothing the surface of the handle and '''radiusing''' the edge.}}

===See also===
* {{l|en|ulna}}
* {{l|en|semidiameter}}
* {{pedia|Radius}}
* {{pedia|Radius (bone)}}

===Anagrams===
* {{anagrams|en|a=adirsu|Darius}}

{{cln|en|nouns with irregular plurals}}
{{C|en|Circle|Bones}}

==Crimean Tatar==
{{crh-variant|c=радиус}}

===Etymology===
{{bor+|crh|ru|радиус}}, from {{der|crh|la|radius}}.

===Noun===
{{head|crh|noun}}

# [[radius#English|radius]] {{gloss|line segment or length of this line segment}}

====Declension====
{{crh-decl|a|q}}

===References===
* {{R:Useinov-Mireev 2002}}
* {{R:crh:Luğatçıq}}

==Danish==
{{wikipedia|lang=da}}

===Etymology===
Borrowed from {{bor|da|la|radius}}.

===Noun===
{{da-noun|g=c|radien|sg-def-2=radiusen|radier|pl-indef-2=radiuser}}

# {{lb|da|geometry}} {{l|en|radius}}

===References===
* {{R:Den Danske Ordbog}}

==Esperanto==

===Verb===
{{eo-head}}

# {{eo-form of|radi|us}}

==Faroese==

===Noun===
{{fo-noun|m|radius|radiusar}}

# {{lb|fo|geometry}} [[radius#English|radius]]

====Declension====
{{fo-decl-noun-m52|radius}}

==French==

===Etymology===
{{bor+|fr|la|radius}}. {{doublet|fr|rai}}, which was inherited.

===Pronunciation===
* {{fr-IPA|radiuss}}
* {{audio|fr|LL-Q150 (fra)-Vaulque-radius.wav}}

===Noun===
{{fr-noun|m}}

# {{lb|fr|skeleton}} [[radius#English|radius]]

===Further reading===
* {{R:fr:TLFi}}

===Anagrams===
* {{l|fr|durais}}

==Ido==

===Verb===
{{head|io|verb form}}

# {{io-form of|radi}}

==Indonesian==
{{wikipedia||lang=id}}

===Etymology===
{{lbor|id|la|radius}}.

===Pronunciation===
* {{IPA|id|/raˈdiʊs/}}
* {{hyphenation|id|ra|di|us}}

===Noun===
{{id-noun|head=|pl=-}}

# {{l|en|radius}}:
## {{lb|id|mathematics}} a line segment between any point of a circle or sphere and its center; the length of this line segment.
##: {{syn|id|jari-jari}}
## {{lb|id|anatomy}} the long bone in the forearm, on the side of the thumb.
##: {{syn|id|pengumpil}}
# [[area]] of a [[circle]], commonly with [[epicenter]] as [[center]].

====Derived terms====
{{der4|id|
| radius pelayaran
}}

===Further reading===
* {{R:KBBI Daring}}

==Latin==

===Etymology===
Of {{unc|la|nocap=1}} origin.<ref>{{R:itc:EDL|head=radius|page=512}}</ref> Some connect it with {{m|la|rādīx}} and {{m|la|rāmus}}. Tucker suggests {{der|la|ine-pro|*neredʰ-||extend forth, rise, outward}} akin to Sanskrit {{m|sa|वर्धते||rise, grow}}, or from {{der|la|grc|ἄρδις||sharp point}}.<ref> Tucker, T.G., Etymological Dictionary of Latin, Ares Publishers, 1976 (reprint of 1931 edition). </ref> May ultimately be from {{der|la|ine-pro|*reh₁t-||bar, beam, stem}}.

===Pronunciation===
* {{la-IPA|radius}}

===Noun===
{{la-noun|radius<2>}}

# a [[staff]], [[rod]]
## a [[spoke]] of a [[wheel]]
## a rod for measurement
## the [[radius]] of a [[circle]]; a rotating [[radial]] [[arm]]
## {{lb|la|weaving}} a [[shuttle]]
## {{lb|la|poetic}} a [[bolt]] or [[shaft]]
## the [[spur]] of a [[bird]]'s [[leg]]
## the tail-[[spine]] of a [[stingray]]
## {{lb|la|anatomy}} the [[radius#English|radius]] {{gl|the outer bone of a [[forearm]]}}
# a [[ray]] of [[light]] {{q|also reflected}}
#* {{Q|la|Virgil|Aeneid|4|118-119|quote=“[...] ubi prīmōs crāstinus ortus<br/>extulerit Tītān, '''radiīs'''que retēxerit orbem.”|trans=“[...] when at tomorrow’s early dawn the Titan [Sun] will have risen, and '''with [his] rays''' revealed the world.”}}
#* {{Q|la|Ovid|Fasti|6|717|quote=At pater Hēliadum '''radiōs''' ubi tīnxerit undīs|trans=But when the father of the Heliades shall have dipped his '''rays''' in the waves [...].<br/>(The father is the sun god; see: {{w|Heliades}}.)}}
## {{q|according to an ancient theory of vision}} a ray extending from the eye to the object seen
# the name of an [[elongated]] variety of [[olive]]
# the name of a rod with which geometers make figures in dust, also known as a [[virga]]

====Declension====
{{la-ndecl|radius<2>}}

====Derived terms====
* {{l|la|radiō}}
* {{l|la|radiolus}}

====Descendants====
{{top2}}
* {{desc|bor=1|sq|rreze}}
* {{desc|rup|aradzã|radzã}}
* {{desc|ca|raig}}
** {{desc|sc|bor=1|unc=1|raxu}}
* {{desc|dlm|rus|ruaz}}
* {{desc|fro|rai}}
** {{desc|fr|rai}}
** {{desc|bor=1|en|ray}}
* {{desc|fur|rai}}
* {{desc|gl|raia|raio|raxo}}
* {{desc|it|raggio}}
** {{desc|scn|raggiu}} {{qual|italianized, palatalized variant}}
* {{desc|mwl|raio}}
* {{desc|mxi|ראיה}}
* {{desc|oc|rai}}
* {{desc|pt|raia|raio}}
* {{desc|ro|rază}}
* {{desc|sc|raju|alt=(ar)raju|ragiu|alt2=(ar)rag(g)iu|arràciu|ràdiu}}
* {{desc|scn|raja}}
* {{desc|es|raya|rayo|raza}}
**  {{desc|bor=1|sc|razu|g=m|raza|g2=f|rasu}}
* {{desc|vec|rajo}}
* {{desc|bor=1|cy|rhaidd}}
{{bottom}}

;Learned borrowings
{{top2}}
* {{desc|bor=1|ca|radi}}
* {{desc|bor=1|it|radio}}
* {{desc|bor=1|en|radius|radio-|radio}}
* {{desc|bor=1|fr|radius}}
* {{desc|bor=1|gl|radio}}
* {{desc|bor=1|de|Radius}}
* {{desc|bor=1|pt|rádio}}
* {{desc|bor=1|ro|radius}}
* {{desc|bor=1|ru|ра́диус}}
* {{desc|bor=1|scn|ràdiu}}
* {{desc|bor=1|es|radio}}
{{bottom}}

===References===
<references/>

===Further reading===
* {{R:OLD|2|radius|1731}}
* {{R:L&S}}
* {{R:Elementary Lewis}}
* {{R:du Cange}}
* {{R:Gaffiot}}
* {{R:Peck}}
* {{R:Smith's Antiquities}}

==Norwegian Bokmål==
{{wikipedia|lang=no}}

===Etymology===
Borrowed from {{bor|nb|la|radius}}.

===Noun===
{{head|nb|noun|g=m|definite singular|radien|or|radiusen|indefinite plural|radier|definite plural|radiene}}

# {{lb|nb|geometry}} {{l|en|radius}}

===References===
* {{R:The Bokmål Dictionary}}

==Norwegian Nynorsk==
{{wikipedia|lang=nn}}

===Etymology===
Borrowed from {{bor|nn|la|radius}}.

===Noun===
{{nn-noun-m1}}

# {{lb|nn|geometry}} {{l|en|radius}}

===References===
* {{R:The Nynorsk Dictionary}}

==Romanian==

===Etymology===
{{bor+|ro|fr|radius}}, {{bor|ro|la|radius}}. Compare the inherited doublet {{doublet|ro|rază|t1=ray|notext=1}}.

===Noun===
{{ro-noun|n|radiusuri}}

# {{lb|ro|anatomy}} {{l|en|radius}} (bone)

====Related terms====
* {{l|ro|radiu}}