1) a bird
2) a cock, a hen
Part of Speech: noun masculine
Probably from a prolonged form of the base of G3735; a bird (as rising in the air), that is, (specifically) a hen (or female domestic fowl): - hen.
Perseus Digital Library
University of Chicago's Logion lexicon
Thayer's dictionary plus other information.
From this site's dictionary (in Italian)
Click on the first column to search for that word as a form of the root ὄρνις; click on the second column to search for that grammatical form of the root ὄρνις; click on the third column to search for that word and grammatical form; click on the total to search for the root ὄρνις.