Of or pertaining to substitution or to a substitute

The act of substituting or the state of being substituted. / A substitute or replacement.

plural of substitution

(philosophy) A logical relationship in which two terms can be mutually substituted without affecting the truth value of any propositions in which the terms occur, thereby establishing that the terms are identical.

Characteristic of, or serving as a substitute

The quality of being substitutable; the capacity to be substituted.

Such that it may be substituted, or used as a replacement or alternative.

plural of substitutable

plural of substituter

A replacement or stand-in for something that achieves a similar result or purpose. / (sports) A player who is available to replace another if the need arises, and who may or may not actually do so.