Meaning of “peep” - Learner’s Dictionary

peep

verb [ I ] uk us /piːp/
peep at/ through/out, etc

to look at something for a short time, often when you do not want other people to see you:

She peeped at them through the fence.
peep through/over/out from, etc

to appear but not be seen completely:

The sun peeped out from behind the clouds.
peep noun [ no plural ]

She took a peep at herself in the mirror.

(Definition of “peep” from the Cambridge Learner’s Dictionary © Cambridge University Press)