concave

English

Top: a spoon with itsconvexside up.
Bottom: a spoon with itsconcaveside up.

A concave polygon.

A concave (concave downwards) function.

Etymology

FromMiddle Englishconcave,fromOld Frenchconcave,fromLatinconcavus.

Pronunciation

• (UK)IPA^(key):/ˈkɒn.keɪv/,/kɒnˈkeɪv/
• (US)IPA^(key):/ˈkɑn.keɪv/,/kɑnˈkeɪv/,/kənˈkeɪv/

  • Audio(US):

    (file)

Adjective

concave(comparativemoreconcave,superlativemostconcave)

1. Curvedlike theinnersurface of asphereor bowl.
2. (geometry,not comparable,of apolygon)Notconvex;having at least one internal angle greater than 180 degrees.
3. (functional analysis,not comparable,of areal-valuedfunctionon thereals)Satisfying the property that all segments connecting two points on the function's graph lie below the function.
4. Hollow;empty.
   • c.1598–1600(date written),William Shakespeare,“As You Like It”,inMr. William Shakespeares Comedies, Histories, & Tragedies[…](First Folio), London:[…]Isaac Iaggard,andEd[ward]Blount,published1623,→OCLC,[Act III, scene iv]:

     asconcave[…]as a worm-eaten nut

Antonyms

• convex

Derived terms

• biconcave
• concavation
• concave envelope
• concave function
• concavely
• concaveness
• concavification
• concavify
• concavity
• concavoconcave
• convexoconcave
• double concave
• nonconcave
• planoconcave
• proconcave
• pseudoconcave
• quasiconcave
• subconcave

Translations

curved inward

• Arabic:مُقَعَّر(muqaʕʕar),مُجَوَّف(mujawwaf)
• Armenian:գոգավոր(hy)(gogavor)
• Asturian:cóncavu
• Bengali:অবতল(bn)(obotol)
• Bulgarian:вдлъбнат(vdlǎbnat)
• Catalan:còncau(ca)
• Chinese:

  Mandarin:Ao(zh)(āo)

• Cornish:kowgrom
• Czech:vydutý,konkávní(cs)
• Danish:konkav
• Dutch:hol(nl)
• Esperanto:kava
• Estonian:nõgus
• Faroese:innskaraður,innhjólaður
• Finnish:kovera(fi),konkaavi(fi)
• French:concave(fr)
• Galician:cóncavo(gl)
• German:konkav(de),nachinnengewölbt,eingewölbt
• Greek:κοίλος(el)(koílos)
• Hawaiian:ʻeʻele
• Hungarian:homorú(hu),konkáv(hu)
• Icelandic:íhvolfur
• Italian:concavo(it)
• Japanese:Ao diện(ja)(おうめん, ōmen)
• Kazakh:ойыс(oiys)
• Korean:요면(yomyeon)
• Latin:concavus
• Maori:areare,kōpapa
• Norwegian:

  Bokmål:konkav

  Nynorsk:konkav

• Persian:کاو(fa)(kâv)
• Polish:wklęsły(pl)
• Portuguese:côncavo(pt)
• Romanian:concav(ro)
• Russian:во́гнутый(ru)(vógnutyj)
• Slovak:dutý,vydutý,konkávny
• Spanish:cóncavo(es)
• Swedish:konkav(sv)
• Tagalog:malukong
• Thai:เว้า(th)(wáo)
• Turkish:konkav(tr),içbükey(tr)
• Tày:boóng
• Vietnamese:lõm(vi)
• Welsh:ceugrwm(cy)m,ceugromf

Noun

concave(pluralconcaves)

1. Aconcavesurface or curve.
2. The vault of the sky.
3. One of the celestialspheresof thePtolemaicorgeocentricmodel of the world.

   Aristotle makes [Fire] to move to the concave of the Moon.- Thomas Salusbury (1661).

4. (manufacturing)An element of a curved grid used to separate desirable material from tailings or chaff inminingandharvesting.
5. (surfing)An indentation running along the base of asurfboard,intended to increaselift.
6. (skateboarding)An indented area on the top of askateboard,providing a position for foot placement and increasing board strength.
7. (gambling)Aplaying cardmade concave for use incheating.

   Coordinate term:convex

Translations

A concave surface or curve

• Bulgarian:вдлъбнатина(bg)(vdlǎbnatina)
• Kurdish:

  Northern Kurdish:rûçal(ku)

• Russian:невы́пуклый(ru)(nevýpuklyj)
• Thai:รูปร่างที่นูน

Verb

concave(third-person singular simple presentconcaves,present participleconcaving,simple past and past participleconcaved)

1. To renderconcave,or increase the degree ofconcavity.

Derived terms

• concaver

Translations

To render concave, or increase the degree of concavity.

• Bulgarian:вдлъбвам(vdlǎbvam)

French

Etymology

InheritedfromOld Frenchconcave,borrowed fromLatinconcavus.

Pronunciation

• Audio:

  (file)

Adjective

concave(pluralconcaves)

1. concave

Descendants

• →Turkish:konkav

Further reading

• “concave”,inTrésor de la langue française informatisé[Digitized Treasury of the French Language],2012.

Italian

Adjective

concave

1. femininepluralofconcavo

Latin

Adjective

concave

1. vocativemasculinesingularofconcavus