Our online medical glossary of medical terms and definitions includes definitions for terms related to treatment, and general medicine
1. A medication or application that has the characteristic of easing pain or protecting from the action of irritants. A mild purgative; a laxative.
2. That which softens or mitigates; that which tends to allay passion, excitement, or pain; a palliative. "There is one sweet Lenitive at least for evils, which Character holds out; so I took it kindly at her hands, and fell asleep." (Sterne)
Origin: Cf. F. Lenitif.
Source: Websters Vocabulary