Concave \Con"cave\ (k[o^][ng]*k[=a]*v" or k[o^]n"-; 277), a. [L. concavus; con- + cavus hollow: cf. F. concave. See Cave a hollow.]

1. Hollow and curved or rounded; vaulted; -- said of the interior of a curved surface or line, as of the curve of the of the inner surface of an eggshell, in opposition to convex; as, a concave mirror; the concave arch of the sky.

2. Hollow; void of contents. [R.]

As concave . . . as a worm-eaten nut. --Shak.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Concave \Con"cave\, n. [L. concavum.]

1. A hollow; an arched vault; a cavity; a recess.

Up to the fiery concave towering hight. --Milton.

2. (Mech.) A curved sheath or breasting for a revolving cylinder or roll.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Concave \Con"cave\, v. t. [imp. & p. p. concaved; p. pr. & vb. n. Concaving.]

To make hollow or concave.

Source: Webster's Revised Unabridged Dictionary (1913)