substitution

noun4

1. •
   The act of substituting or the state of being substituted.

   • In this football tournament, three substitutions can be made during the match.
2. •
   The replacement of an atom, or group of atoms, in a compound, with another.
3. •
   The expansion of the lexicon of a language by native means in correspondence to a foreign term.
4. •
   A substitute or replacement.

   • Gary is off this weekend, so Jeff will be his substitution.