Metaphor: a short similitude; a figure of speech in which a word or phrase is applied to an object.

For example: The soldier was a lion in combat.

From Greek μεταφερω (to transfer), which further derives from μετα (over) and φερω (carry).

Mixed metaphors are fun. It’s not rocket surgery.  We’ll burn that bridge when we come to it.  Lately, I’ve been burning the midnight oil at both ends….