Avian etymology in English

English word avian comes from English -ian, Latin avis ((figuratively) omen, portent. A bird.)

Dictionary entry	Language	Definition
-ian	English (en)	(as a noun) Having a certain profession.. (as a noun) One from, belonging to, relating to, or like.. (as an adjective) From, related to, or like.
avis	Latin (lat)	(figuratively) omen, portent. A bird.
avian	English (en)	Characteristic of or pertaining to birds, or to bird-like or flying creatures. A bird-like or flying creature.. A bird.

Avian etymology