surrogate

noun

1. A substitute (usually of a person, position or role).

   “A mixture of horseradish and mustard often serves as a surrogate for wasabi.”

2. A person or animal that acts as a substitute for the social or pastoral role of another, such as a surrogate parent.
3. (British)A deputy for a bishop in granting licences for marriage.
4. (US)A politician or person of influence campaigning for a presidential candidate.
5. (US)A judicial officer of limited jurisdiction, who administers matters of probate and intestate succession and, in some cases, adoptions.
6. Any of a range of Unicode codepoints which are used in pairs in UTF-16 to represent characters beyond the Basic Multilingual Plane.
7. An ersatz good.
8. (abbreviation, alt-of, ellipsis)Ellipsis of surrogate key.

adj

1. Of, concerning, relating to or acting as a substitute.

verb

1. (transitive)To replace or substitute something with something else; to appoint a successor.