(especially of a bird) to make a short high sound or sounds. (Cambridge Dictionary)
(of a small bird or an insect) make a short, sharp, high-pitched sound. (Oxford Dictionaries)
(of a person) say something in a lively and cheerful way. (Oxford Dictionaries)
When a bird or an insect such as a cricket or grasshopper chirps, it makes short high-pitched sounds. (Collins Dictionary)
To make a chirp or a sound resembling a chirp. (Merriam – Webster)
Chirping bird society.
Chirp and Gay