- a person or thing acting or serving in place of another.
- (formerly) a person who, for payment, served in an army or navy in the place of a conscript.
- 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.
- to put (a person or thing) in the place of another.
- to take the place of; replace.
- Chemistry. to replace (one or more elements or groups in a compound) by other elements or groups.
- to act as a substitute.
- of or relating to a substitute or substitutes.
- composed of substitutes.
Origin of substitute
- (often foll by for) to serve or cause to serve in place of another person or thing
- chem to replace (an atom or group in a molecule) with (another atom or group)
- logic maths to replace (one expression) by (another) in the context of a third, as replacing x + y for x in 3 x = k gives 3 x + 3 y = k
- a person or thing that serves in place of another, such as a player in a game who takes the place of an injured colleague
- (as modifier)a substitute goalkeeper Often shortened to: sub
- grammar another name for pro-form
- Canadian another name for supply teacher
- nautical another word for repeater (def. 5)
- (formerly) a person paid to replace another due for military service
Word Origin and History for intersubstitutability
early 15c. in transitive sense, 1888 as intransitive, from Latin substitutus, past participle of substituere (see substitution). Related: Substituted; substituting.
"one who acts in place of another," early 15c., from Old French substitute and directly from Latin substitutus, past participle of substituere (see substitution). Team sports sense is from 1849.