v. & n.
--v.
1. intr. (usu. of small birds, grasshoppers, etc.) utter a short sharp high-pitched note.
2 tr. & intr. (esp. of a child) speak or utter in a lively or jolly way.
--n. a chirping sound.
Derivatives:
chirper n.
Etymology: ME, earlier chirk, chirt: imit.