Answer: concessive

AnswerCrossword Clue
concessiveCharacterized by, or tending to concession
concessive(of a preposition or conjunction) Introducing a phrase or clause denoting a circumstance that might be expected to preclude the action of the main clause, but does not (e.g., in spite of, although)
concessive(of a phrase or clause) Introduced by a concessive preposition or conjunction
concessiveimplying concession; as, a concessive conjunction