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

---

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

See Examples For:

substitution

That substitution was a clever one by Maresca and brave too, because while Ndiaye is better than Cherki defensively, he is also a ball-carrier who travels with the ball better too.

From BBC ● Sep. 13, 2026

With Rushing back on the IL for the same elbow injury, Feduccia can also serve as a left-handed bat off the bench, and Alfonzo gives the team more substitution flexibility.

From Los Angeles Times ● Sep. 9, 2026

The substitution models suggested that replacing one daily serving of a sugary beverage with whole fruit could be associated with a 22% lower risk of developing high blood pressure.

From Science Daily ● Jul. 23, 2026

Bearings benefit from low substitution risk — all robots will need them, Jonas said.

From MarketWatch ● Jul. 15, 2026

Unlike a substitution cipher, it doesn’t replace any of the letters in the original message.

From "The Woman All Spies Fear" by Amy Butler Greenfield