concessive

Concise Oxford English Dictionary © 2008 Oxford University Press:
concessive/kənˈsesɪv/

▶adjective

• 1 characterized by or tending to concession.

• 2 Grammar (of a preposition or conjunction) introducing a phrase or clause denoting a circumstance which might be expected to preclude the action of the main clause, but does not (e.g. in spite of, although).