permutation in WordNet English dictionary

1. complete change in character or condition
   "the permutations...taking place in the physical world"- Henry Miller
   permutation 
   
2. the act of changing the arrangement of a given number of elements
   permutation 
   
3. act of changing the lineal order of objects in a group
   permutation 
   
4. an event in which one thing is substituted for another
   "the replacement of lost blood by a transfusion of donor blood"
   substitution  permutation  transposition  replacement  switch