Available Definitions:
1) n. - The act of permuting; exchange of the thing for another; mutual transference; interchange.
2) n. - The arrangement of any determinate number of things, as units, objects, letters, etc., in all possible orders, one after the other; -- called also alternation. Cf. Combination, n., 4.
3) n. - Any one of such possible arrangements.
4) n. - Barter; exchange.