substitution

noun

sub·​sti·​tu·​tion ˌsəb-stə-ˈtü-shən 

-ˈtyü-

1

a

: the act, process, or result of substituting one thing for another

b

: replacement of one mathematical entity by another of equal value

2

: one that is substituted for another

substitutional

ˌsəb-stə-ˈtü-sh(ə-)nəl 

-ˈtyü-

adjective

substitutionally adverb

substitutionary

ˌsəb-stə-ˈtü-shə-ˌner-ē 

-ˈtyü-

adjective

Examples of substitution in a Sentence

The coach made three substitutions in the second half of the game.

I'd prefer rice with my steak instead of potatoes, but the menu says “no substitutions.”

Substitution of applesauce for oil is one way of reducing the fat in recipes.

The cookbook has a long list of substitutions for ingredients that may be hard to find.

Recent Examples on the Web

Morocco's second-half success was thanks to sharp substitutions. — Marlene Lenthang, NBC news, 25 June 2026

Manager Mauricio Pochettino made three second-half substitutions that beefed up the US lineup, sending in Sergiño Dest, Alex Freeman and attacker Alejandro Zendejas. — Kyle Feldscher, CNN Money, 25 June 2026

That busing substitution will remain in effect until further notice. — Darius Johnson, CBS News, 25 June 2026

In a 2008 paper for The Journal of Wealth Management , researchers Anita Arora, Lauren Capp and Gary Smith tested 50 substitutions made since the Dow expanded to 30 stocks in 1928. — Deena Zaidi, CNBC, 24 June 2026

Word History

Etymology

Middle English substitucion, from Middle French, from Late Latin substitution-, substitutio, from substituere

First Known Use

14th century, in the meaning defined at sense 1a

Phrases Containing substitution

• substitution cipher

Rhymes for substitution

• absolution
• allocution
• attribution
• comminution
• constitution
• contribution
• convolution
• destitution
• devolution
• diminution
• dissolution
• distribution

Medical Definition

substitution

noun

sub·​sti·​tu·​tion ˌsəb-stə-ˈt(y)ü-shən 

1

: a chemical reaction in which one or more atoms or groups in a molecule are replaced by equivalent atoms or groups to form at least two products

especially : the replacement of hydrogen in an organic compound by another element or group

2

a

: the turning from an obstructed desire to another desire whose gratification is socially acceptable

b

: the turning from an obstructed form of behavior to a different and often more primitive expression of the same tendency

a substitution neurosis

c

: the reacting to each of a set of stimuli by a response prescribed in a key

a substitution test for speed of learning new responses

Legal Definition

substitution

noun

sub·​sti·​tu·​tion ˌsəb-stə-ˈtü-shən, -ˈtyü- 

: the substituting of one person or thing for another: as

a

in the civil law of Louisiana : a disposition not in trust by which a donee, heir, or legatee is charged to hold property transferred and return it to a third person compare fidei commissum, vulgar substitution

Note: Substitutions are prohibited.

b

: replacement of a party to an action with a successor or representative upon motion to the court when the party is unable to continue litigating (as because of death, incompetency, transfer of interest, or loss of the office for which the party was suing or being sued in an official capacity)

c

: the replacement of a new agreement or obligation for an old one see also novation

substitutional

-shə-nəl 

adjective

substitutionary

-shə-ˌner-ē 

adjective