radius

See also: Radius, RADIUS, and radíus

English

A radius shown in red

Etymology

Borrowed from Latin radius (“ray”). Doublet of ray.

Pronunciation

• enPR: rā'-dē-əs, IPA^(key): /ˈɹeɪ.di.əs/

• Audio (US):

  (file)

• Rhymes: -eɪdiəs
• Hyphenation: ra‧di‧us

Noun

radius (plural radii or radiuses)

1. (anatomy) The long bone in the forearm, on the side of the thumb.
2. (zoology) The lighter bone (or fused portion of bone) in the forelimb of an animal.
3. (entomology) One of the major veins of the insect wing, between the subcosta and the media
4. (geometry) A line segment between any point of a circle or sphere and its center.
5. (geometry) The length of this line segment.
6. 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.

Synonyms

• (vein of insect wing): R

Related terms

• radial
• radiate, radiation

Translations

bone (human)

• Arabic: كُعْبُرَة f (kuʕbura)

  Egyptian Arabic: كعبرة f (kuʿbura)

• Armenian: ճաճանչոսկր (hy) (čačančʻoskr)
• Bulgarian: лъчева кост f (lǎčeva kost)
• Catalan: radi (ca) m
• Chinese:

  Mandarin: 橈骨／桡骨 (zh), 桡骨 (zh) (ráogǔ)

• Czech: vřetenní kost f
• Dutch: spaakbeen (nl) n, radius (nl) m
• Esperanto: radiuso
• Finnish: värttinäluu (fi)
• French: radius (fr) m
• German: Speiche (de) f, Radius (de) m
• Greek: κερκίδα (el) f (kerkída)
• Hungarian: orsócsont (hu)
• Ido: radiuso (io)
• Irish: gaghéag f
• (deprecated template usage) {{trans-mid}}
• Italian: radio (it) m
• Japanese: 橈骨 (ja) (とうこつ, tōkotsu)
• Kalmyk: шу (şu)
• Korean: 노뼈 (ko) (noppyeo), 요골 (yogol)
• Malay: radius
• Maori: āpiti
• Old English: hresel
• Polish: kość promieniowa f pl
• Portuguese: rádio (pt) m
• Russian: лучева́я кость f (lučevája kostʹ)
• Serbo-Croatian: žbica (sh) f, palčana kost f
• Spanish: radio (es) m
• Telugu: రత్ని (te) (ratni)
• Ukrainian: променева кістка f (promeneva kistka)
• Volapük: radiut
• Welsh: radiws m

line segment

• Afrikaans: radius
• Arabic: نُصْف قُطْر m (nuṣf quṭr), شُعَاع m (šuʕāʕ)
• Armenian: շառավիղ (hy) (šaṙaviġ)
• Basque: erradio
• Belarusian: ра́дыус m (rádyus)
• Breton: skin m
• Bulgarian: ра́диус m (rádius)
• Burmese: အချင်းဝက် (my) (a.hkyang:wak)
• Catalan: radi (ca) m
• Cebuano: tungatid
• Chinese:

  Mandarin: 半徑／半径 (zh) (bànjìng), 半径 (zh) (bànjìng)

• Czech: poloměr (cs) m
• Danish: radius (da)
• Dutch: straal (nl) f
• Esperanto: radiuso
• Estonian: raadius
• Finnish: säde (fi)
• French: rayon (fr) m
• Friulian: rai m
• Galician: raio (gl) m
• Georgian: რადიუსი (radiusi)
• German: Radius (de) m
• Greek: ακτίνα (el) f (aktína)
• Gujarati: ત્રિજ્યા (gu) f (trijyā)
• Hebrew: רַדְיוּס (he) m (rádyus)
• Hindi: त्रिज्या (hi) f (trijyā)
• Hungarian: sugár (hu)
• Icelandic: radíus (is) m, geisli (is) m
• Ido: radiuso (io)
• Indonesian: radius (id)
• Irish: ga m
• Italian: raggio (it)
• Japanese: 半径 (ja) (はんけい, hankei)
• (deprecated template usage) {{trans-mid}}
• Korean: 반지름 (ko) (banjireum), 반경 (ko) (ban'gyeong)
• Latvian: rādiuss m
• Lithuanian: spindulys m
• Macedonian: радиус m (radius), полупре́чник m (polupréčnik, literally “semidiameter”)
• Malay: jejari
• Maori: pūtoro
• Marathi: त्रिज्या f (trijyā)
• Norwegian:

  Bokmål: radius (no) m

  Nynorsk: radius m

• Persian: شعاع (fa) (šo'â')
• Polish: promień (pl) m
• Portuguese: raio (pt) m
• Punjabi: ਰੇਡੀਅਸ (reḍīasa)
• Romanian: rază (ro) f
• Russian: ра́диус (ru) m (rádius)
• Scottish Gaelic: spòg f
• Serbo-Croatian:

  Cyrillic: полупречник m

  Roman: poluprečnik m

• Slovak: polomer m
• Slovene: polmer (sl) m
• Spanish: radio (es) m
• Swedish: radie (sv)
• Tagalog: lihit
• Thai: รัศมี (th) (rát-sà-mǐi)
• Turkish: yarıçap (tr)
• Ukrainian: ра́діус (uk) m (rádius)
• Urdu: رداس m (radās)
• Vietnamese: bán kính (vi)
• Volapük: raid
• Welsh: radiws m
• Yiddish: ראַדיוס m (radyus)

length of this line segment

• Armenian: շառավիղ (hy) (šaṙaviġ)
• Belarusian: ра́дыус m (rádyus)
• Bulgarian: ра́диус m (rádius)
• Catalan: radi (ca) m
• Czech: poloměr (cs) m
• Dutch: straal (nl) f
• Finnish: säde (fi)
• French: rayon (fr) m
• German: Halbmesser (de) m, Radius (de) m
• Hungarian: sugár (hu)
• Icelandic: radíus (is) m, geisli (is) m
• Irish: ga m
• Italian: raggio (it) m
• Japanese: 半径 (ja) (はんけい, hankei)
• Korean: 반지름 (ko) (banjireum)
• Macedonian: радиус m (radius), полупре́чник m (polupréčnik)
• (deprecated template usage) {{trans-mid}}
• Malay: jejari
• Norwegian:

  Bokmål: radius (no) m

  Nynorsk: radius m

• Polish: promień (pl) m
• Portuguese: raio (pt) m
• Russian: ра́диус (ru) m (rádius)
• Serbo-Croatian:

  Cyrillic: полупречник m

  Roman: poluprečnik m

• Slovene: polmer (sl) m
• Spanish: radio (es) m
• Ukrainian: ра́діус (uk) m (rádius)
• Volapük: raid
• Welsh: radiws m

See also

• ulna
• semidiameter
• Template:projectlink

Anagrams

• Darius

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Crimean Tatar

Etymology

Borrowed from Latin radius.

Noun

radius

1. radius (line segment or length of this line segment)

Declension

Declension of radius

nominative	radius
genitive	radiusnıñ
dative	radiusqa
accusative	radiusnı
locative	radiusta
ablative	radiustan

References

• Mirjejev, V. A., Usejinov, S. M. (2002) Ukrajinsʹko-krymsʹkotatarsʹkyj slovnyk [Ukrainian – Crimean Tatar Dictionary]‎^[1], Simferopol: Dolya, →ISBN

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Danish

Etymology

Borrowed from Latin radius.

Noun

radius c (singular definite radien or radiusen, plural indefinite radier or radiuser)

1. (geometry) radius

References

• “radius” in Den Danske Ordbog

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Esperanto

Verb

radius

1. conditional of radii

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French

Etymology

Borrowed from Latin radius. Doublet of rai, which was inherited.

Pronunciation

• IPA^(key): /ʁa.djys/

• Audio:

  (file)

Noun

radius m (plural radius)

1. (anatomy) radius

Further reading

• “radius”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012.

Anagrams

• durais

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Ido

Verb

(deprecated template usage) radius

1. conditional of radiar

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Latin

Etymology

Of uncertain origin. Some have tried to connect it to rādīx. Tucker suggests Proto-Indo-European *neredʰ- (“extend forth, rise, outward”) akin to Sanskrit वर्धते (vardhate, “rise, grow”), or from Ancient Greek ἄρδις (árdis, “sharp point”). May ultimately be from Proto-Indo-European *reh₁t- (“bar, beam, stem”).

Pronunciation

• (Classical Latin) IPA^(key): /ˈra.di.us/, [ˈräd̪iʊs̠]
• (modern Italianate Ecclesiastical) IPA^(key): /ˈra.di.us/, [ˈräːd̪ius]

Noun

radius m (genitive radiī or radī); second declension

1. ray (of light)
2. staff, rod
3. spoke (of a wheel)

Declension

Second-declension noun.

Case	Singular	Plural
Nominative	radius	radiī
Genitive	radiī radī1	radiōrum
Dative	radiō	radiīs
Accusative	radium	radiōs
Ablative	radiō	radiīs
Vocative	radie	radiī

¹Found in older Latin (until the Augustan Age).

Derived terms

• radiō

Descendants

• Albanian: rreze (borrowing)
• Aromanian: aradzã, radzã
• Catalan: radi (borrowing), raig
• Dalmatian: rus, ruaz
• English: radius (borrowing), ray (via Old French), radio-, radio
• French: radius (borrowing), rai
• Friulian: rai
• Galician: radio (borrowing), raia, raio, raxo
• German: Radius (borrowing)
• Italian: radio (borrowing), raggio
• Mirandese: raio

• Mozarabic: rayo
• Occitan: rai
• Portuguese: rádio (borrowing), raia, raio
• Romanian: radius (borrowing), rază
• Russian: ра́диус (rádius) (borrowing)
• Sardinian: ragiu
• Spanish: radio (borrowing), raya, rayo, raza
• Venetian: rajo

References

• “radius”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• “radius”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• radius in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
• radius in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.
• “radius”, in Harry Thurston Peck, editor (1898), Harper's Dictionary of Classical Antiquities, New York: Harper & Brothers
• “radius”, in William Smith et al., editor (1890), A Dictionary of Greek and Roman Antiquities, London: William Wayte. G. E. Marindin

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Norwegian Bokmål

Etymology

Borrowed from Latin radius.

Noun

radius m (definite singular radien or radiusen, indefinite plural radier, definite plural radiene)

1. (geometry) radius

References

• “radius” in The Bokmål Dictionary.

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Norwegian Nynorsk

Etymology

Borrowed from Latin radius.

Noun

radius m (definite singular radiusen, indefinite plural radiusar, definite plural radiusane)

1. (geometry) radius

References

• “radius” in The Nynorsk Dictionary.

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Romanian

Etymology

Borrowed from French radius, Latin radius. Compare the inherited doublet rază (“ray”).

Noun

radius n (plural radiusuri)

1. (anatomy) radius (bone)

Related terms

• radiu