Definition of Permutation

Noun: permutation  ,pur-myoo'tey-shun

1. An event in which one thing is substituted for another
   - substitution, transposition, replacement, switch
    
2. The act of changing the arrangement of a given number of elements
    
3. Complete change in character or condition
   "the permutations...taking place in the physical world"
    
4. Act of changing the lineal order of objects in a group

See also:
permutableness
permutational