concave

noun

The concave mirror reflected the light beams.

意味（1）

A concave surface or curve.

意味（2）

The vault of the sky.

意味（3）

One of the celestial spheres of the Ptolemaic or geocentric model of the world.

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

意味（4）

意味（5）

(surfing) An indentation running along the base of a surfboard, intended to increase lift.

意味（6）

意味（7）

(gambling) A playing card made concave for use in cheating.

Coordinate term: convex