radius

See also: Radius, RADIUS, and radíus

English

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.
   • 1808, John Barclay, The Muscular Motions of the Human Body‎, →OCLC, page 396:

     It is also obvious, and proved by experiment, that the rotatory motions observed in the hand proceed from the rotatory motions of the radius.

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; the vein running along the costal edge of the discal cell.
5. (geometry) A line segment between any point of a circle or sphere and its center.

   Fatima claims to have visited all the bars within a five-mile radius of her Manhattan apartment.

   • 1994, Viacheslav V. Nikulin, Igor R. Shafarevich, translated by Miles Reid, Geometries and Groups, Springer, page 194:

     We start with spherical geometries. The two geometries on spheres of radiuses R₁ and R₂ are obviously identical if R₁ = R₂; moreover, the converse also holds.

   • 2016, Jubee Sohn, Ho Seong Hwang, Margaret J. Geller, Antonaldo Diaferio, Kenneth J. Rines, Myung Gyoon Lee, Gwang-Ho Lee, “Compact Groups of Galaxies with Complete Spectroscopic Redshifts in the Local Universe”, in JKAS‎, volume 2015:

     The velocity dispersions of early- and late-type galaxies in compact groups change little with groupcentric radius; the radii sampled are less than ${\displaystyle 100~h^{-1}}$ kpc, smaller than the radii typically sampled by members of massive clusters of galaxies.

6. (geometry) The length of this line segment.
   • 1998, Dieter Schuocker, Handbook of the Eurolaser Academy, Springer Science & Business Media, →ISBN, page 51:

     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 ...

7. 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.
   • 1674, Robert Hooke, Animadversions on the Firſt Part of the Machina Coelestis of the […] Aſtronomer Johannes Hevelius […] ‎, page 43:

     […] 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; […]

8. (graph theory) The minimum eccentricity of any vertex, for a given graph.

Synonyms

• (vein of insect wing): R

Derived terms

• atomic radius
• Bohr radius
• circumradius
• covalent radius
• Debye radius
• Earth radius
• equiradiate
• exradius
• gyradius
• gyroradius
• Hill radius
• hydraulic radius
• hyperradius
• inradius
• interradius
• ionic radius
• metallic radius
• potato radius
• radian
• radion
• radius arm
• radius bar
• radius of action
• radius of convergence
• radius of curvature
• radius of gyration
• radius rod
• radius vector
• Roche radius
• Schwarzschild radius
• sight radius
• triradius
• van der Waals radius

Related terms

• radial
• radiad
• radiate, radiation

Translations

bone (human)

Arabic: كُعْبُرَة f (kuʕbura) Egyptian Arabic: كعبرة f (kuʕbura) Armenian: ճաճանչոսկր (hy) (čačančʻoskr) Bulgarian: лъчева кост f (lǎčeva kost) Catalan: radi (ca) m Chinese: Mandarin: 橈骨 / 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 Italian: radio (it) m Japanese: 橈骨 (ja) (とうこつ, tōkotsu) Kalmyk: шу (şu) Kannada: ಮುಂಗೈ ಮೂಳೆ (kn) (muṅgai mūḷe) Kazakh: кәрі жілік (kärı jılık) Korean: 노뼈 (ko) (noppyeo), 요골 (yogol) Kurdish: Northern Kurdish: kewere Malay: radius (ms) Maori: āpiti Mongolian: Cyrillic: шуу (mn) (šuu), шуу яс (šuu jas) (China) Old English: hresel Persian: زند زبرین (zand-e zabarin) Polish: kość promieniowa (pl) f Portuguese: rádio (pt) m Romanian: radius (ro) n 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) Vietnamese: xương quay Volapük: radiut Welsh: gwäell y fraich f

line segment

Afrikaans: radius Arabic: نِصْف قُطْر m (niṣf quṭr), شُعَاع m (šuʕāʕ) Armenian: շառավիղ (hy) (šaṙaviġ) Basque: erradio Belarusian: ра́дыус m (rádyus) Breton: skin (br) 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) Czech: poloměr (cs) m Danish: radius (da) Dutch: straal (nl) f Esperanto: radiuso Estonian: raadius (et) Faroese: radius m Finnish: säde (fi) French: rayon (fr) m Friulian: rai m Galician: raio (gl) m Georgian: რადიუსი (radiusi) German: Radius (de) m, Halbmesser (de) m (rare) 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), jari-jari (id) Irish: ga m Italian: raggio (it) Japanese: 半径 (ja) (はんけい, hankei) Kannada: ತ್ರಿಜ್ಯ (kn) (trijya) Kazakh: радиус (radius) Korean: 반지름 (ko) (banjireum), 반경 (ko) (ban'gyeong) Kurdish: Northern Kurdish: nîvtîre Latvian: rādiuss (lv) m Lithuanian: spindulys m Macedonian: радиус m (radius), полупре́чник m (polupréčnik, literally “semidiameter”) Malay: jejari (ms) Maori: pūtoro Marathi: त्रिज्या f (trijyā) Mongolian: радиус (mn) (radius) 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 Telugu: వ్యాసార్థము (vyāsārthamu) Thai: รัศมี (th) (rát-sà-mǐi) Turkish: yarıçap (tr) Ukrainian: ра́діус (uk) m (rádius) Urdu: رداس m (radās), نصف قطر (nisf-qutr) 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 Chinese: Mandarin: 半徑 / 半径 (zh) (bànjìng) Czech: poloměr (cs) m Dutch: straal (nl) f Finnish: säde (fi) French: rayon (fr) m German: Radius (de) m, Halbmesser (de) m (rare) Hindi: त्रिज्या (hi) f (trijyā) 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) Malay: jejari (ms) Marathi: त्रिज्या f (trijyā) Norwegian: Bokmål: radius (no) m Nynorsk: radius m Polish: promień (pl) m Portuguese: raio (pt) m Romanian: rază (ro) f Russian: ра́диус (ru) m (rádius) Serbo-Croatian: Cyrillic: полупречник m Roman: poluprečnik m, polumjer (sh) m (Croatia) Slovene: polmer (sl) m Spanish: radio (es) m Swedish: radie (sv) Ukrainian: ра́діус (uk) m (rádius) Volapük: raid Welsh: radiws m

Verb

radius (third-person singular simple present radiuses, present participle radiusing, simple past and past participle radiused)

1. (transitive) To give a rounded edge to.
   • 2014, Anil Mital, Anoop Desai, Anand Subramanian, Product Development, page 358:

     A comfortable grip is ensured by smoothing the surface of the handle and radiusing the edge.

See also

• ulna
• semidiameter
• Radius on Wikipedia.Wikipedia
• Radius (bone) on Wikipedia.Wikipedia

Anagrams

• Darius

Crimean Tatar

Other scripts
Cyrillic	радиус
Roman

Etymology

Borrowed from Russian радиус (radius), from Latin radius.

Noun

radius

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

Declension

Declension of radius

	singular	plural
nominative	radius	radiuslar
genitive	radiusnıñ	radiuslarnıñ
dative	radiusqa	radiuslarğa
accusative	radiusnı	radiuslarnı
locative	radiusta	radiuslarda
ablative	radiustan	radiuslardan

References

• Mirjejev, V. A.; Usejinov, S. M. (2002), Ukrajinsʹko-krymsʹkotatarsʹkyj slovnyk [Ukrainian – Crimean Tatar Dictionary]‎, Simferopol: Dolya, →ISBN
• “radius”, in Luğatçıq (in Russian)

Danish

Danish Wikipedia has an article on:

radius

Wikipedia ^da

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

Esperanto

Verb

radius

1. conditional of radii

Faroese

Noun

radius m (genitive singular radius, plural radiusar)

1. (geometry) radius

Declension

Declension of radius (m52)

	singular		plural
	indefinite	definite	indefinite	definite
nominative	radius	radiusin	radiusar	radiusarnir
accusative	radius	radiusin	radiusar	radiusarnar
dative	radiusi	radiusinum	radiusum	radiusunum
genitive	radius	radiussins	radiusa	radiusanna

French

Etymology

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

Pronunciation

• IPA^(key): /ʁa.djys/

• Audio:

  (file)

• Audio (France (Vosges)):

  (file)

Noun

radius m (invariable)

1. (anatomy) radius

Further reading

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

Anagrams

• durais

Ido

Verb

radius

1. conditional of radiar

Indonesian

Indonesian Wikipedia has an article on:

radius

Wikipedia ^id

Etymology

Learned borrowing from Latin radius.

Pronunciation

• IPA^(key): /raˈdiʊs/
• Hyphenation: ra‧di‧us

Noun

radius (plural radius-radius)

1. radius:
   1. (mathematics) a line segment between any point of a circle or sphere and its center; the length of this line segment

      Synonyms: jari-jari, ruji-ruji

   2. (anatomy) the long bone in the forearm, on the side of the thumb

      Synonym: pengumpil

2. area of a circle, commonly with epicenter as center

Derived terms

• radius pelayaran

Further reading

• “radius”, in Kamus Besar Bahasa Indonesia [Great Dictionary of the Indonesian Language] (in Indonesian), Jakarta: Agency for Language Development and Cultivation – Ministry of Education, Culture, Research, and Technology of the Republic of Indonesia, 2016