union vs separation

union and separation both are nouns.

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

union (noun)	separation (noun)
the act of making or becoming a single unit	the social act of separating or parting company
the act of pairing a male and female for reproductive purposes	the act of dividing or disconnecting
a device on a national flag emblematic of the union of two or more sovereignties (typically in the upper inner corner)	(law) the cessation of cohabitation of man and wife (either by mutual agreement or under a court order)
the occurrence of a uniting of separate parts	sorting one thing from others
an organization of employees formed to bargain with the employer	the distance between things
a political unit formed from previously independent people or organizations	coming apart
a set containing all and only the members of two or more given sets	the termination of employment (by resignation or dismissal)
healing process involving the growing together of the edges of a wound or the growing together of broken bones	the space where a division or parting occurs
the state of being joined or united or linked	the state of lacking unity
the state of being a married couple voluntarily joined for life (or until divorce)

union (adjective)	separation (adjective)
of trade unions