The Oxford Thesaurus An A-Z Dictionary of Synonyms - chirp v.

1) tweet, peep, twitter, chirrup, warble, trill, cheep, chitter, chirr, pipe: I was awakened by the birds, chirping away in the forest. --n. 2) tweet, peep, twitter, chirrup, warble, trill, cheep, chitter, chirr: The canary gave two chirps and jumped onto its perch.