Staffer (noun)

1. A person who works as a member of a particular organization's staff.
2. A person who works in a particular position within an organization, such as an administrative assistant or a campaign aide.

Origin:

Late 19th century: from staff + -er.

Examples:

1. She was a staffer in the President's office.
2. He was a staffer on the Senator's campaign.
3. The staffer was responsible for scheduling meetings.
4. The staffer was in charge of communications.
5. The company has many experienced staffers.