Lenitive first appears in English in the 15th century. It derives from the Latin verb lenire ("to soften or soothe"), which was itself formed from the adjective lenis, meaning "soft" or "mild." Lenire also gave us the adjective lenient, which usually means "tolerant" or "indulgent" today but in its original sense carried the meaning of "relieving pain or stress." Often found in medical contexts, lenitive can also be a noun referring to a treatment (such as a salve) with soothing or healing properties.
Word History
Etymology
Middle English lenitif, from Middle French, from Medieval Latin lenitivus, from Latin lenitus, past participle of lenire