junior

little, mean, small

minute, petty

jerkwater, one-horse, second-class, second-rate, two-bit

associate, auxiliary, secondary, subsidiary

attendant, follower, retainer

domestic, menial, steward

flunky (also flunkey), henchman, lackey, minion

adjutant, aid, aide, assistant, coadjutor, deputy, second, second fiddle

helpmate, helpmeet, mate, sidekick