remission n.

c. 1200, remissioun, "forgiveness or pardon (of sins)," from Old French remission "forgiveness (of sins), relief" (12c.) and directly from Latin remissionem (nominative remissio) "relaxation, diminishing," etymologically "a sending back, sending away," noun of action from past-participle stem of remittere "slacken, let go, abate" (see remit).

From late 14c. as "release from duty or obligation." Of diseases, fevers, "abatement, temporary subsidence," from early 15c. General sense of "diminution of force or effects" is from c. 1600. By 1736 as "abatement of penalty or punishment."