1. to peep or chirp, as a chick does. 2. A short, high-pitched radio signal 3. pip-pip-pip: sound of footsteps (“Misoso: Once Upon a Time Tales from Africa”, by Verna Aardema)
onomatopoeia: 1. the naming of a thing or action by a vocal imitation of the sound associated with it (as buzz, hiss) 2. the use of words whose sound suggests the sense