re ‧ tain ‧ er AC /rɪˈteɪnə $ -ər/ BrE AmE noun [countable]
1 . an amount of money paid to someone, especially a lawyer, so that they will continue to work for you in the future
2 . British English a reduced amount of rent that you pay for a room, flat etc when you are not there, so that it will still be available when you return
3 . American English a plastic and wire object that you wear in your mouth to make your teeth stay straight SYN brace British English
4 . old use a servant