division vs separation

division and separation both are nouns.

Word	Noun	Adjective	Verb	Adverb
division	Yes	No	No	No
separation	Yes	No	No	No

As nouns, separation is a hypernym of division; that is, separation is a word with a broader meaning than division:

As nouns, separation is a hypernym of division; that is, separation is a word with a broader meaning than division:

division: the act of dividing or partitioning; separation by the creation of a boundary that divides or keeps apart
separation: the act of dividing or disconnecting

division (noun)	separation (noun)
the act or process of dividing	the social act of separating or parting company
an arithmetic operation that is the inverse of multiplication; the quotient of two numbers is computed	the act of dividing or disconnecting
the act of dividing or partitioning; separation by the creation of a boundary that divides or keeps apart	(law) the cessation of cohabitation of man and wife (either by mutual agreement or under a court order)
one of the portions into which something is regarded as divided and which together constitute a whole	sorting one thing from others
discord that splits a group	the distance between things
an army unit large enough to sustain combat	coming apart
a group of ships of similar type	the termination of employment (by resignation or dismissal)
a unit of the United States Air Force usually comprising two or more wings	the space where a division or parting occurs
an administrative unit in government or business	the state of lacking unity
(botany) taxonomic unit of plants corresponding to a phylum
(biology) a group of organisms forming a subdivision of a larger category
a league ranked by quality