substitution

Etymology

From Middle French substitution, from Late Latin substitutio.

noun

1. The act of substituting or the state of being substituted.
   In this football tournament, three substitutions can be made during the match.
2. A substitute or replacement.
   Gary is off this weekend, so Jeff will be his substitution.
3. (chemistry, especially organic chemistry) The replacement of an atom, or group of atoms, in a compound, with another.
4. (linguistics) The expansion of the lexicon of a language by native means in correspondence to a foreign term.
   Coordinate term: importation