imperil vs peril

imperil is not a noun while peril is a noun.

Word	Noun	Adjective	Verb	Adverb
imperil	No	No	Yes	No
peril	Yes	No	Yes	No

As verbs, imperil and peril are synonyms defined as:

Other synonyms of imperil include endanger, jeopardise, jeopardize, menace, threaten.

imperil (noun)	peril (noun)
	a venture undertaken without regard to possible loss or injury
	a source of danger; a possibility of incurring loss or misfortune
	a state of danger involving risk

imperil (verb)	peril (verb)
pose a threat to; present a danger to	put in a dangerous, disadvantageous, or difficult position
	pose a threat to; present a danger to