discernment vs sagacity

discernment and sagacity both are nouns.

Word	Noun	Adjective	Verb	Adverb
discernment	Yes	No	No	No
sagacity	Yes	No	No	No

As nouns, discernment and sagacity are synonyms defined as:

discernment and sagacity: the mental ability to understand and discriminate between relations

Other synonyms of discernment include judgement, judgment, sagaciousness.

discernment (noun)	sagacity (noun)
the trait of judging wisely and objectively	the trait of forming opinions by distinguishing and evaluating
the mental ability to understand and discriminate between relations	the mental ability to understand and discriminate between relations
the cognitive condition of someone who understands
perception of that which is obscure
delicate discrimination (especially of esthetic values)