mid-14c., from northern England dialect, from Old Norse egg, which vied with Middle English eye, eai (from Old English æg) until finally displacing it after 1500; both are from Proto-Germanic *ajja(m) (cf. Old Saxon, Middle Dutch, Dutch, Old High German, German ei, Gothic ada), probably from PIE *owyo-/*oyyo- "egg" (cf. Old Church Slavonic aja, Russian jajco, Breton ui, Welsh wy, Greek oon, Latin ovum); possibly derived from root *awi- "bird." Caxton (15c.) writes of a merchant (probably a north-country man) in a public house on the Thames who asked for eggs:
She did, however, recognize another customer's request for "eyren." Bad egg in the figurative sense is from 1855. To have egg on (one's) face "be made to look foolish" is attested by 1948.
Eggs Benedict attested by 1898. The figure of speech represented in to have all (one's) eggs in one basket is attested by 1660s.