moderation (n.)

early 15c., moderacioun, "quality of being moderate or temperate; a lessening of rigor or severity," from Old French moderacion (14c.) "alteration, modification; mitigation, alleviation" and directly from Latin moderationem (nominative moderatio) "a controlling, guidance, government, regulation; moderation, temperateness, self-control," noun of action from past-participle stem of moderari "to regulate, mitigate, restrain, temper, set a measure, keep (something) within measure," from PIE root *med- "take appropriate measures." Meaning "act of moderating or restraining" is from 1520s.