concave

Adj

1. Curved like the inner surface of a sphere or bowl.
2. (not-comparable) Not convex; having at least one internal angle greater than 180 degrees.
3. (not-comparable) Satisfying the property that all segments connecting two points on the function's graph lie below the function.
4. Hollow; empty.

Noun

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

Verb

To render concave, or increase the degree of concavity.

Pronounced as (IPA)

/ˈkɒn.keɪv/

Etymology

Inherited from Middle English: concave

In summary

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

Synonyms

hollow

sunken

cavity

dent

dished

depression

indented

intaglio

concavity

be hollowed out

vault

re-entrant

dented

groove

hemisphere

hole

🕳️

holed

holey

hollowness

indentation

low-lying

muddy

pocket

pothole

recession

scarf

🧣

scoop

sink down

sulcus

tumble down

caved in

concave surface

curving inward

bowl-shaped

concave camber

notch board

splineway

flattened out

holl

make hollow

rearward face

appropriate

patellate

arch

boggy

cave

cave in

cavernous

chamfer

collapse