succedaneum

A substitute.

One who or that which supplies the place of another; that which is used for something else; a substitute.

One who, or that which, succeeds to the place of another; that which is used for something else; a substitute

A substitute, replacement for something else, particularly of a medicine used in place of another.

(medicine) something that can be used as a substitute (especially any medicine that may be taken in place of another)