substitution

/ˈsʌbstəˌtuʃən/

/səbstɪˈtuʃən/

Other forms: substitutions

The noun substitution refers to the act of replacing one thing with another. Your football coach might make a substitution by sending you onto the field to take over for a player who is tired or injured.

Substitution comes from the Middle French word of the same spelling, meaning "a putting in place of another." You might notice that substitution contains the root word substitute, and that's a good way to remember the meaning of the word. In school, a substitute is a temporary teacher who fills in when your regular teacher is out — in other words, a substitution has been made until your teacher returns.

Definitions of substitution

1. noun

   the act of putting one thing or person in the place of another: "he sent Smith in for Jones but the substitution came too late to help"
   synonyms: commutation, exchange

   types:

   replacement, replacing

   the act of furnishing an equivalent person or thing in the place of another

   subrogation

   (law) the act of substituting of one creditor for another

   ablactation, weaning

   the act of substituting other food for the mother's milk in the diet of a child or young mammal

   novation

   (law) the replacement of one obligation by another by mutual agreement of both parties; usually the replacement of one of the original parties to a contract with the consent of the remaining party

   pitching change

   replacing a pitcher in baseball

   supersedure, supersession

   act of replacing one person or thing by another especially one held to be superior

   displacement, supplanting

   act of taking the place of another especially using underhanded tactics

   type of:

   change

   the action of changing something
2. noun

   an event in which one thing is substituted for another
   synonyms: permutation, replacement, switch, transposition

   type of:

   fluctuation, variation

   an instance of change; the rate or magnitude of change