Open English Wordnet
Nouns
(n)interval, separationthe distance between things“fragile items require separation and cushioning” (n)separationsorting one thing from others“the separation of wheat from chaff”,
“the separation of mail by postal zones” (n)separationthe social act of separating or parting company“the separation of church and state” (n)separationthe space where a division or parting occurs“he hid in the separation between walls” (n)separationthe termination of employment (by resignation or dismissal) (n)legal separation, separation(law) the cessation of cohabitation of man and wife (either by mutual agreement or under a court order)