outlier vs deviation

outlier and deviation both are nouns.

Word	Noun	Adjective	Verb	Adverb
outlier	Yes	No	No	No
deviation	Yes	No	No	No

As nouns, deviation is a hypernym of outlier; that is, deviation is a word with a broader meaning than outlier:

outlier: an extreme deviation from the mean
deviation: the difference between an observed value and the expected value of a variable or function

outlier (noun)	deviation (noun)
an extreme deviation from the mean	deviate behavior
a person who lives away from his place of work	a turning aside (of your course or attention or concern)
	the error of a compass due to local magnetic disturbances
	the difference between an observed value and the expected value of a variable or function
	a variation that deviates from the standard or norm