Concave

from Wikipedia, the free encyclopedia

concave stands for:

the property of a mathematical function, see convex and concave functions
inwardly curved surfaces, see convex and concave surfaces

lens surfaces curved inwards, see lens (optics) #Different lens shapes

inwardly curved mirror surfaces, see concave mirror

See also:

convex

Wiktionary: concave - explanations of meanings, word origins, synonyms, translations