Yours, Etc.: Origins and Uses of 8 Sign-Offs
1660s, from French pronation, from Medieval Latin pronationem (nominative pronatio), noun of action from past participle stem of Late Latin pronare (see pronate).
pronation pro·na·tion (prō-nā'shən)n.
The act of pronating.
The condition of being pronated, especially the condition of having flat feet.