v. Obs. rare–1. [f. L. tranquillitāt-em (see next), or obs. F. tranquilliter (Cotgr.): see -ATE3 7.] trans. = TRANQUILLIZE.

1

1657.  Tomlinson, Renou’s Disp., 629. Theriack complects all antidotes, which … tranquillitate diseases.

2