substitution

UK: /ˌsʌbstɪˈtjuːʃ^ən/

Collins Concise English Dictionary © HarperCollins Publishers::

substitution / ˌsʌbstɪˈtjuːʃən/ noun

1. the act of substituting or state of being substituted
2. something or someone substituted

WordReference Random House Learner's Dictionary of American English © 2025

sub•sti•tute /ˈsʌbstɪˌtut, -ˌtyut/   n., v., -tut•ed, -tut•ing, adj. 
n. 

1. a person or thing serving in place of another:
   [countable] The coach sent in a substitute when his star player was injured.
   [uncountable] For most of us there is simply no substitute for hard work.

v. 

2. to put (a person or thing) in the place of another:
   [~ + object + for + object] We substituted fish for meat several times a week.
3. to act as a substitute:
   [no object] substituting when the regular teachers were sick.

adj. [before a noun]

4. of or relating to a substitute or substitutes:
   a substitute teacher.

sub•sti•tu•tion, n. 

[uncountable] the substitution of one budget problem for another.

[countable] The coach made a few substitutions in the defensive team.

See -stit-.

WordReference Random House Unabridged Dictionary of American English © 2025

sub•sti•tute  (sub′sti to̅o̅t′, -tyo̅o̅t′), n., v., -tut•ed, -tut•ing, adj. 
n. 

1. a person or thing acting or serving in place of another.
2. American History, Military (formerly) a person who, for payment, served in an army or navy in the place of a conscript.
3. Grammar a word that functions as a replacement for any member of a class of words or constructions, as do in He doesn't know but I do.

v.t. 

4. to put (a person or thing) in the place of another.
5. to take the place of; replace.
6. Chemistry to replace (one or more elements or groups in a compound) by other elements or groups.

v.i. 

7. to act as a substitute.

adj. 

8. of or pertaining to a substitute or substitutes.
9. composed of substitutes.

• Latin substitūtus (past participle of substituere to put in place of ), equivalent. to sub- sub- + -stitū-, combining form of statū-, past participle stem of statuere (see substituent) + -tus past participle suffix
• Middle English 1350–1400

sub′sti•tut′a•ble, adj. 
sub′sti•tut′a•bil′i•ty, n. 
sub′sti•tut′er, n. 
sub′sti•tut′ing•ly, adv. 
sub′sti•tu′tion, n. 
sub′sti•tu′tion•al, sub•sti•tu•tion•ar•y  (sub′sti to̅o̅′shə ner′ē, -tyo̅o̅′-), adj.  sub′sti•tu′tion•al•ly, adv. 
Synonyms

• 1. alternative, replacement, equivalent.