n. & v.
n. 1 a (also attrib.) a person or thing acting or serving in place of another. b an artificial alternative to a natural substance (butter substitute). 2 Sc. Law a deputy.
v. 1 intr. & tr. (often foll. by for) act or cause to act as a substitute; put or serve in exchange (substituted for her mother; substituted it for the broken one). 2 tr. (usu. foll. by by, with) colloq. replace (a person or thing) with another. 3 tr. Chem. replace (an atom or group in a molecule) with another. substitutable adj. substitutability n. substitution n. substitutional adj. substitutionary adj. substitutive adj.
[ ME f. L substitutus past part. of substituere (as SUB-, statuere set up) ]