deputy

One appointed as the substitute of others, and empowered to act for them, in their name or their behalf; a substitute in office

(mining, historical) A person employed to install and remove props, brattices, etc. and to clear gas, for the safety of the miners.

(France): A member of the Chamber of Deputies, formerly called Corps Législatif

(Ireland): a member of Dáil Éireann, or the title of a member of Dáil Éireann. (Normally capitalised in both cases)

(United States): a law enforcement officer who works for the county sheriff's office; a deputy sheriff or sheriff's deputy; the entry level rank in such an agency