Lewis Short
(adjective) : adversātīvus, a, um, id.
* Adversative; in gram.: conjunctiones adversativae, which have an adversative signif. as opp. to each other, as tamen, quamquam, etsi, etiamsi, etc., Prisc. 1030 P.; while quamquam, etsi, etc., we now designate as concessive in relation to tamen.
Charlton T. Lewis, Charles Short, A Latin Dictionary