con·cave (kŏn-kāv, kŏnkāv′)
Curved like the inner surface of a sphere.
A concave surface, structure, or line.
tr.v. con·caved, con·cav·ing, con·caves
To make concave.
[Middle English, from Latin concavus : com-, intensive pref.; see COM- + cavus, hollow; see keuə- in the Appendix of Indo-European roots.]
(click for a larger image)concave
left to right: biconcave,
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.