Permutation /(pẽr`mū̇"tā"snŭn)/

Per·mu·ta·tion

Permutation

n.
  1. The act of permuting; exchange of the thing for another; mutual transference; interchange.
    The violent convulsions and permutations that have been made in property.
  2. 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. (Math.)
  3. Barter; exchange. (Law)

Phrases & Compounds
Permutation lock
a lock in which the parts can be transposed or shifted, so as to require different arrangements of the tumblers on different occasions of unlocking.