sitter
noun
1
a woman who works in a bar, encouraging male customers to drink and to buy them drinks US, 1987.
2
a hostess in a brothel, neither prostitute nor madam AUSTRALIA, 1985.
3
a person who monitors and comforts an alcohol or drug addict who is going through the initial stages of detoxification. A term used in twelve-step recovery programmes such as Alcoholics Anonymous US, 1998.
4
a person who guides another or others through an LSD experience. An allusion to the practice of babysitting US, 1966.
5
in pool, a ball perched on the lip of a pocket US, 1924