How many letters does the top answer for “to chirp, as a young bird.” have?

The most common answer is cheep (5 letters).

Crossword clue: to chirp, as a young bird.

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

cheep 5 letters web-def

the short weak cry of a young bird

a young bird. thackeray. 50% similar → birdikin

the study of young birds. 50% similar → neossology