Su`pi*na"tion (?), n. [L. supinare, supinatum, to bend or lay backward, fr. supinus supine: cf. F. supination. See Supine.] Physiol. (a)
The act of turning the hand palm upward; also, position of the hand with the palm upward.
(b)
The act or state of lying with the face upward. Opposed to pronation.
© Webster 1913.