Surrogate

/ˈsɜːr.əˌɡeɪt/

Synonyms

Slang Meanings

A term for someone who is temporarily taking over someone else's responsibilities.
She was acting as a surrogate while her boss was on leave.
In some circles, it refers to someone who fills in during a friendship or a relationship.
After they broke up, he was just a surrogate for her loneliness.