concave

Meanings

Adjective

• curved like the inner surface of a sphere or bowl
• not convex; having at least one internal angle greater than 180 degrees.
• satisfying the property that all segments connecting two points on the function's graph lie below the function.
• hollow; empty

Noun

• A concave surface or curve.
• The vault of the sky.
• One of the celestial spheres of the Ptolemaic or geocentric model of the world.
• An element of a curved grid used to separate desirable material from tailings or chaff in mining and harvesting.
• An indentation running along the base of a surfboard, intended to increase lift.
• An indented area on the top of a skateboard, providing a position for foot placement and increasing board strength.
• A playing card made concave for use in cheating.

Verb

• To render concave, or increase the degree of concavity.

Related

Opposite words

• convex

Origin

• From Middle English concave, from Old French concave, from Latin concavus.