difficulty vs deterrent

difficulty and deterrent both are nouns.

Word	Noun	Adjective	Verb	Adverb
difficulty	Yes	No	No	No
deterrent	Yes	Yes	No	No

As nouns, deterrent is a hyponym of difficulty; that is, deterrent is a word with a more specific, narrower meaning than difficulty:

difficulty: the quality of being almost beyond one's ability to deal with and requiring a great effort to achieve a positive result
deterrent: something immaterial that interferes with or delays action or progress

difficulty (noun)	deterrent (noun)
an effort that is inconvenient	something immaterial that interferes with or delays action or progress
the quality of being almost beyond one's ability to deal with and requiring a great effort to achieve a positive result

difficulty (adjective)	deterrent (adjective)
	tending to deter