1660s, "painting or drawing done in different tints of a single color," from Latinized form of Greek monokhrōmos, also monokhrōmatos, "of a single color," from monos "single, alone" (from PIE root *men- (4) "small, isolated") + khrōma (genitive khrōmatos) "color, complexion, skin" (see chroma). As an adjective from 1849. Photographic sense is recorded from 1940.
Monmouth
mono-
mono
monoceros
monochromatic
monochrome
monocle
monocular
monoculture
monogamous
monogamy