What is a synonym for chaperone?

Here are some synonyms for chaperone, depending on the context:

Formal:

* Escort

* Attendant

* Guardian

* Supervisor

* Mentor

Informal:

* Companion

* Guide

* Watcher

* Babysitter

* Lookout

Specific to a particular situation:

* Duenna (a woman who chaperones a young unmarried woman)

* Matron of honor (a woman who acts as a chaperone for the bride)

* Best man (a man who acts as a chaperone for the groom)

The best synonym to use will depend on the specific situation and the tone you want to convey.