\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}.