surrogate

Short definition from Wiktionary

Noun

1. 1
   A substitute (usually of a person, position or role).
2. 2
   A person or animal that acts as a substitute for the social or pastoral role of another, such as a surrogate parent.
3. 3
   A deputy for a bishop in granting licences for marriage.
4. 4
   A politician or person of influence campaigning for a presidential candidate.
5. 5
   A judicial officer of limited jurisdiction, who administers matters of probate and intestate succession and, in some cases, adoptions.
6. 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. 7
   An ersatz good.
8. 8
   Ellipsis of surrogate key.

Adjective

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

Verb

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