concave

UK: /ˈkɒnkeɪv/, /kɒnˈkeɪv/

US: /kɑnˈkeɪv, ˈkɑnkeɪv/

US: (adj., v. kon kāv′, kon′kāv; n. kon′kāv)

Inflections of 'concave' (v): (⇒ conjugate)

concaves

v 3rd person singular

concaving

v pres p

concaved

v past

concaved

v past p

WordReference Random House Learner's Dictionary of American English © 2026

con•cave /kɑnˈkeɪv, ˈkɑnkeɪv/   adj. 

1. Mathematics curved inward like the inside of a sphere:
   a concave lens.
   Compare convex.

con•cave•ly, adv. 
con•cave•ness, n. 
con•cav•i•ty/kɑnˈkævɪti/  ; n. [uncountable* countable] , pl. -ties. 

WordReference Random House Unabridged Dictionary of American English © 2026

con•cave  (adj., v. kon kāv′, kon′kāv;n. kon′kāv), adj., n., v., -caved, -cav•ing. 
adj. 

1. Mathematics curved like a segment of the interior of a circle or hollow sphere;
   hollow and curved. Cf. convex (def. 1).
2. Mathematics [Geom.] (of a polygon) having at least one interior angle greater than 180°.
3. [Obs.] hollow.

n. 

4. Mathematics a concave surface, part, line, or thing.
5. Mechanical Engineering [Mach.] a concave piece, as one against which a drum rotates.

v.t. 

6. to make concave.

• Latin concavus, hollow. See con-, cave
• Middle French)
• late Middle English (1375–1425

con•cave′ly, adv. 
con•cave′ness, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

concave / ˈkɒnkeɪv kɒnˈkeɪv/ adjective

1. curving inwards
2. having one or two surfaces curved or ground in the shape of a section of the interior of a sphere, paraboloid, etc: a concave lens
3. an obsolete word for hollow

verb

1. (transitive) to make concave

Compare convexEtymology: 15th Century: from Latin concavus arched, from cavus hollow

ˈconcavely adverb

ˈconcaveness noun