The Collaborative International Dictionary
Ommatidium \Om`ma*tid"i*um\, n.; pl. Ommatidia. [NL., dim. of Gr. ?, ?, the eye.] (Zo["o]l.) One of the single eyes forming the compound eyes of crustaceans, insects, and other invertebrates; one of the eyes of an ommateum.
Wiktionary
n. (plural of ommatidium English)
WordNet
n. any of the numerous small cone-shaped eyes that make up the compound eyes of some arthropods
[also: ommatidia (pl)]
See ommatidium
Usage examples of "ommatidia".
The adult's chiton was purple, and purple was a color that had been described to him and now he knew what it was and the ceramic inlay in the doctor's forehead was a single bar of silver crossed by two bars of gold and his ommatidia were red with gold and yellow central bands and they gleamed in the light of the room and .
Then a shadow darkened his ommatidia and he keeled over on his left side.
His eyes were simple, and there were no ommatidia to throw back rainbows at the stupefied watchers, but they gleamed a little in their own way from beneath slightly slanted brows.