2. The state of being substituted for another.

3. The office or authority of one acting for another; delegated authority. [R.] Shak.

4. (Civil Law)

Defn: 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. Burrill.

5. (Theol.)

Defn: The doctrine that Christ suffered vicariously, being substituted for the sinner, and that his sufferings were expiatory.

6. (Chem.)

Defn: The act or process of substituting an atom or radical for another atom or radical; metethesis; also, the state of being so substituted. See Metathesis.

SUBSTITUTIONAL
Sub`sti*tu"tion*al, a.

Defn: Of or pertaining to substitution; standing in the place of
another; substituted.
— Sub`sti*tu"tion*al*ly, adv.