word-forming element meaning "egg, eggs," from Greek ōon "egg," cognate with Latin ovum, Old Norse egg,from PIE *ōwyo‑, *ōyyo‑ "egg," which perhaps is a derivative of the root *awi- "bird."
onus
onward
onwards
onymous
onyx
oo-
oocyst
oocyte
oodles
oogenesis
ooh