Other forms: peeping, peeps, peeped
To peep is to look through a small opening, or quickly and secretly. Peep through the curtains, peep round the door, have a peep.
It suggests being unseen, which is why peeping carries a whiff of trespass. As a noun a peep is such a look, and also a small sound — not a peep out of you, meaning not a word. Peephole is the small lens in a front door. Note peep out, meaning to become just visible; and that peep is also the sound a small bird makes.
1verbpeepTo look through a small opening.
“She peeped round the door and went straight out again.”
2nounquickA quick look, or a small sound.
“There was not a peep out of any of them for about an hour.”
peep is a quick look or small sound.
Middle English pepen appeared in the fifteenth century and is probably imitative of the bird sound, with the looking sense borrowed from the idea of a chick just showing itself.
Middle English
pepen
English, today
peep
From Middle English pepen. Compare Dutch piepen (“peep”), German Low German piepen (“to peep”), German piepen and pfeifen, all probably imitative of the sound.
Etymology from Wiktionary, CC BY-SA