The Dictionary.com Word of the Day today is coterminous (koh-TUR-muh-nuhs, adjective: 1. Having the same or coincident boundaries. 2. Having the same scope, range of meaning, duration.)
To illustrate the best way to use the word in a sentence, Dictionary.com has turned to the ultimate authoritative source, Reason's own Brian Doherty:
That kind of sociological prejudice rests on a false supposition, . . . that "social" and "governmental" are coterminous, and that anyone who is against governmental action is therefore essentially "atomistic."
-- Brian Doherty, "Cybersilly", Reason, August/September 2000
Read the the article that vaulted Brian to lexicographical fame here.