a dental 'assistant' [=a person whose job is to help a dentist]
She works as a 'sales assistant' [='salesclerk'] at Macy's.
a wealthy executive who has a personal 'assistant'
(..) Now get back to work. Where is Rin? What? Don't you dump her on me! You said you wanted an assistant. That's perfect. Give the girl to Rin. - Oh, great. - Sen, get going. Right. (..)2001 Spirited Away