v. & n.
--v.
1. intr. (of or like a bird) emit a succession of light tremulous sounds.
2 tr. utter or express in this way.
--n.
1. the act or an instance of twittering.
2 colloq. a tremulously excited state.
Derivatives:
twitterer n. twittery adj.
Etymology: ME, imit.: cf. -ER(4)