a person who assists or gives aid and support; helper.

a person who is subordinate to another in rank, function, etc.; one holding a secondary rank in an office or post

He was assistant to the office manager.

something that aids and supplements another.

a faculty member of a college or university who ranks below an instructor and whose responsibilities usually include grading papers, supervising laboratories, and assisting in teaching.

assisting; helpful.

serving in an immediately subordinate position; of secondary rank

an assistant coach.

noun

abettor , accessory , accomplice , adherent , adjunct , aide , ally , appointee , apprentice , associate , attendant , auxiliary , backer , backup * , coadjutant , coadjutor , collaborator , colleague , companion , confederate , cooperator , deputy , fellow worker , flunky * , follower , friend , gofer * , help , helpmate , mate , partner , patron , peon * , representative , right-hand person , secretary , subordinate , supporter , temp , temporary worker , adjutant , helper , lieutenant , second , adjuvant , aid , aider , coperator , confrre , hand , henchman , lackey , subsidiary

adjective

accessory , ancillary , collateral , contributory , subsidiary , supportive