peep vs peek

peep and peek both are nouns.

Word	Noun	Adjective	Verb	Adverb
peep	Yes	No	Yes	No
peek	Yes	No	Yes	No

As nouns, peep and peek are synonyms defined as:

peep (noun)	peek (noun)
a secret look	a secret look
the short weak cry of a young bird

peep (verb)	peek (verb)
appear as though from hiding	throw a glance at; take a brief look at
make high-pitched sounds
speak in a hesitant and high-pitched tone of voice
look furtively
cause to come into view