substitute (n.) Look up substitute at Dictionary.com
"one who acts in place of another," early 15c., from Middle French substitut (noun use) and directly from Latin substitutus, past participle of substituere "put in place of another" (see substitution). Military draft sense is from 1777, American English. Team sports sense is from 1849. Of foodstuffs, from 1879. As an adjective from early 15c.
substitute (v.) Look up substitute at Dictionary.com
early 15c. (transitive), from Latin substitutus, past participle of substituere "put in place of another" (see substitution). Transitive use is from 1888. Related: Substituted; substituting.