ADVERSATIVE
adversative, oppositive
(adjective) expressing antithesis or opposition; “the adversative conjunction ‘but’ in ‘poor but happy’”
Source: WordNet® 3.1
Etymology
Adjective
adversative (not comparable)
(linguistics) Expressing opposition or difference.
(linguistics) Expressing adverse effect.
Noun
adversative (plural adversatives)
(rare, dated) Something, particularly a clause or conjunction, which is adversative.
Source: Wiktionary
Ad*ver"sa*tive, a. Etym: [L. adversativus, fr. adversari.]
Definition: Expressing contrariety, opposition, or antithesis; as, an
adversative conjunction (but, however, yet, etc. ); an adversative
force.
– Ad*ver"sa*tive*ly, adv.
Ad*ver"sa*tive, n.
Definition: An adversative word. Harris.
Source: Webster’s Unabridged Dictionary 1913 Edition