1590s, "white of an egg," from Latin albumen (ovi) "white (of an egg)," literally "whiteness," from the neuter of albus "white" (see alb). The organic substance (which exists nearly pure in egg whites) so called from 1800, also known as albumin (1869, from French albumine).
"from the beginning," Latin, literally "from the egg," from ab "from, away from" (see ab-) + ablative of ovum "egg" (see ovum). The expression is said to refer to the Roman custom of beginning the meal with eggs, as also in the expression ab ovo usque ad mala, "from the egg to the apples" (Horace), hence "from the beginning to the end" (compare early 20c. soup to nuts).
"that part of the female animal in which eggs are generated," 1650s, from Modern Latin ovarium "ovary" (16c.), from Medieval Latin ovaria "the ovary of a bird" (13c.), from Latin ovum "egg," from PIE *ōwyo‑, *ōyyo‑ "egg," which is perhaps a derivative of the root *awi- "bird." In classical Latin, ovarius meant "egg-keeper," but Thomson ("Autumn") used ovarious (adj.) for "consisting of eggs."
"louse egg," Middle English nite, from Old English hnitu, from Proto-Germanic *hnitu- (source also of Norwegian nit, Middle Dutch nete, Dutch neet, Middle High German niz, German Niß), from PIE root *knid- "egg of a louse" (source also of Russian, Polish gnida, Czech knida; Greek konis, genitive konidos "egg of a louse").
also caviare, "roe of certain large fish, salted and served as food," 1550s, from French caviar (16c.), from Italian caviaro (modern caviale) or Turkish khaviar, from Persian khaviyar, from khaya "egg," from Middle Persian khayak "egg," from Old Iranian *qvyaka-, diminutive of *avya- (from PIE *ōwyo‑, *ōyyo‑ "egg," which is perhaps a derivative of the root *awi- "bird"). The second element is Persian dar "bearing." The Russian name is ikra.