That which is palliative relieves and soothes, but isn’t expected to cure. A heating pack is a commonly employed palliative for temporarily reducing the pain of strained muscles.
From the French palliatif, which in turn came from the Middle Latin palliates, palliative was first recorded as an adjective in the 1540’s, and then later as a noun in 1724. To palliate is to alleviate without curing, so it makes sense that a palliative is the agent for this type of relief. “Life as we find it, is too hard for us: it brings us too many pains, disappointments and impossible tasks,” said the founder of psychoanalysis Sigmund Freud. “In order to bear it, we cannot dispense with palliative measures…”