The definition of a substitution is a replacement.
An example of a substitution is a teacher filling in for an absent teacher.
the substituting of one person or thing for another
- a. The act or process of substituting: the substitution of human workers with robots.b. An instance of this: made several substitutions to the recipe.
- One that is substituted; a substitute; a replacement: proposed drug therapy as a substitution for surgery.
- sub′sti·tu′tion·al sub′sti·tu′tion·ar′y
substitution - Legal Definition
The selection of an individual or a thing to take the place of another; the process of one thing taking another’s place or one person acting in lieu of another.