Webster's Revised Unabridged Dictionary · 1913

Chirp

Chirp , intransitive verb

[Of imitative orgin. Compare Chirk, Chipper, Cheep, Chirm, Chirrup.]

To make a shop, sharp, cheerful, as of small birds or crickets.

Chirp , noun

A short, sharp note, as of a bird or insect.
The chirp of flitting bird. — Bryant