sub·sti·tu·tion /ˌsʌbstəˈtuʃən, ˈtju-/
1. The act of substituting or putting one person or thing in the place of another; as, the substitution of an agent, attorney, or representative to act for one in his absense; the substitution of bank notes for gold and silver as a circulating medium.
2. The state of being substituted for another.
3. The office or authority of one acting for another; delegated authority. [R.]
4. Civil Law The designation of a person in a will to take a devise or legacy, either on failure of a former devisee or legatee by incapacity or unwillingness to accept, or after him.
5. Theol. The doctrine that Christ suffered vicariously, being substituted for the sinner, and that his sufferings were expiatory.
6. Chem. The act or process of substituting an atom or radical for another atom or radical; metathesis; also, the state of being so substituted. See Metathesis.
n 1: an event in which one thing is substituted for another; "the
replacement of lost blood by a transfusion of donor
blood" [syn: permutation, transposition, replacement,
2: the act of putting one thing or person in the place of
another: "he sent Smith in for Jones but the substitution
came too late to help" [syn: exchange, commutation]