ommatidium

From the stem form of Ancient Greek ὄμμα (ómma, “eye”) + -idium.

• IPA^(key): /ɒməˈtɪdɪəm/

ommatidium (plural ommatidia)

1. (zoology) One of the conical substructures which make up the eyes of invertebrates.
   • 1996: the ‘compound’ eyes of insects [...] are made up of large numbers of facets or ommatidia, and in this sense, our own eyes are ‘simple’. — Michael J. Roberts, Spiders of Britain and Northern Europe (Collins 1996, p. 12)

• (Classical) IPA^(key): /om.maˈti.di.um/, [ɔm.maˈtɪ.di.ũ]

ommatidium n (genitive ommatidiī); second declension

1. ommatidium

Second declension.