a person whose rank is immediately below that of the head of an organization or a department, and who is in charge when the head is not there: He was appointed to the Paris office, serving as deputy to the bureau chief. You will be required to act as deputy in the Sales Manager's absence.

a person appointed or elected as assistant to a public official, serving as successor in the event of a vacancy. a person representing a constituency in certain legislative bodies.

: a person appointed to act for or in place of another 2 : an assistant who usually takes charge when his or her superior is absent

The duties of a deputy vary on their line of work or place of employment. In law enforcement, a deputy is primarily in charge of conducting investigations on crimes and arresting criminals, performing regular patrols on streets, responding to calls of distress, and assisting citizens in calamities, disasters, accidents, or any forms of threat.