Collins English-English Dictionary

permutation ["p3ːmjυ'teɪʃən]

1. 1. n a group formed in this way. The number of permutations of n objects taken r at a time is n!/(n--r)! _nP_r

2. 2. n a fixed combination for selections of results on football pools perm

3. 3. n

4. 4. n [maths] 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

5. 5. n Compare combination

6. 6. n a combination of items made by reordering

7. 7. n an alteration; transformation

8. 8. n [Etymology] C14: from Latin permutatio, from permutare to change thoroughly; see mutation