English to English
1. an event in which one thing is substituted for another
the replacement of lost blood by a transfusion of donor blood
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
3. 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.