Capable of being used as a substitute; valid as a replacement or alternate item. / Capable of being substituted.

present participle of substitute

In a substitutive manner.

Characteristic of, or serving as a substitute

Of or pertaining to substitution or to a substitute

plural of substitutability

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

plural of substitutable

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

(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.