mitigate

From Middle English mitigaten, meaning to soothe pain, calm swelling, or ease the mind, borrowed from Latin mītigāre, itself from mītis, meaning gentle, mild, or ripe.

In Middle English the word covered a wide range of easings — relieving pain, calming swelling, even soothing hemorrhoids or checking something until it stopped — before narrowing toward the more general sense of lessening severity.

It shares its root with mītis, the Latin word for something gentle or ripe, showing that the idea of 'mitigating' something is really about making it soft or mild again.