substitution

British  

/ ˌsʌbstɪˈtjuːʃən /

noun

1. the act of substituting or state of being substituted

2. something or someone substituted

3. maths the replacement of a term of an equation by another that is known to have the same value in order to simplify the equation

4. maths logic

   1. the uniform replacement of one expression by another

   2. an expression so derived from another

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Explanation

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.

Example Sentences

Or he can push for a rate cut to keep credit flowing and let high prices call forth new supply, substitution and efficiency.

From MarketWatch • May 22, 2026

The bank expects resilient demand and cash flow across the sector, supported by stimulus safeguarding local supply chains and acceleration of import substitution, to partially offset prolonged volatility risks.

From The Wall Street Journal • Mar. 25, 2026

Phil Foden's stoppage-time appearance in Manchester City's Carabao Cup final victory over Arsenal felt like a "charity" substitution, says former England captain Wayne Rooney.

From BBC • Mar. 23, 2026

With the substitution exposed, Fox claimed the error was inadvertent.

From Salon • Mar. 9, 2026

It was merely the substitution of one piece of nonsense for another.

From "1984" by George Orwell