the act of permuting or permutating; alteration; transformation.
2.
Mathematics.
the act of changing the order of elements arranged in a particular order, as abc into acb, bac, etc., or of arranging a number of elements in groups made up of equal numbers of the elements in different orders, as a and b in ab and ba; a one-to-one transformation of a set with a finite number of elements.
an ordered arrangement of the numbers, terms, etc, of a set into specified groups: the permutations of a, b, and c, taken two at a time, are ab, ba, ac, ca, bc, cb
a group formed in this way. The number of permutations of n objects taken r at a time is n!/(n–r)! nPrCompare combination (sense 6)
2.
a combination of items made by reordering
3.
an alteration; transformation
4.
a fixed combination for selections of results on football pools Usually shortened to perm
Derived Forms
permutational, adjective
Word Origin
C14: from Latin permūtātiō, from permūtāre to change thoroughly; see mutation
mid-14c., from Old French permutacion "change, shift" (14c.), from Latin permutationem (nominative permutatio) "a change, alteration, revolution," noun of action from past participle stem of permutare "change thoroughly, exchange," from per- "thoroughly" (see per) + mutare "to change" (see mutable).
mathematics 1. An ordering of a certain number of elements of a given set. For instance, the permutations of (1,2,3) are (1,2,3) (2,3,1) (3,1,2) (3,2,1) (1,3,2) (2,1,3). Permutations form one of the canonical examples of a "group" - they can be composed and you can find an inverse permutation that reverses the action of any given permutation. The number of permutations of r things taken from a set of n is n P r = n! / (n-r)! where "n P r" is usually written with n and r as subscripts and n! is the factorial of n. What the football pools call a "permutation" is not a permutation but a combination - the order does not matter. 2. A bijection for which the domain and range are the same set and so f(f'(x)) = f'(f(x)) = x. (2001-05-10)