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A long-term romantic relationship between two unmarried, unengaged people, who are generally considered to be a married or engaged couple for all purposes.
Jack and Jill have been together almost seven years and still no engagement ring. It's only a matter of time, though. They're totally in a terminal relationship.

This party is a terrible place to meet women. They're all married, engaged or in terminal relationships.
by maxkeepsitreal1 February 07, 2010