word-forming element used in English from c. 1300 and meaning "against, in opposition; in return; corresponding," from Anglo-French countre-, French contre-, from Latin contra "opposite, contrary to, against, in return," also used as a prefix (see contra (prep., adv.)). A doublet of contra-. In some cases it probably represents a purely English use of counter (adv.).
late 14c., reformacioun, "restoration, re-establishment;" early 15c., "improvement, alteration for the better," from Old French reformacion and directly from Latin reformationem (nominative reformatio), noun of action from past-participle stem of reformare "to form again, change, transform, alter," from re- "again" (see re-) + formare "to form" (see form (n.)).
With capital R-, in reference to the great 16c. European religious revolution, it is attested by 1540s, borrowed from Luther. The movement began as a bid to "reform" doctrines and practices of the Church of Rome.