1. rotation of the hands and forearms so that the palms face downward;
The Collaborative International Dictionary of English v.0.48:
Pronation \Pro*na"tion\, n. [Cf. F. pronation.] (Physiol.)
(a) The act of turning the palm or palmar surface of the
(b) That motion of the forearm whereby the palm or palmar,
surface is turned downward.
(c) The position of the limb resulting from the act of
pronation. Opposed to supination.
WordNet (r) 3.0 (2006):
n 1: rotation of the hands and forearms so that the palms face
downward [ant: supination]