Noun

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