keep back phrasal verb ( see also ↑ keep )
1 . keep something ↔ back to deliberately not tell someone all that you know about something:
I got the feeling he was keeping something back.
2 . keep something ↔ back to not show your feelings, even though you want to very much:
She was struggling to keep back the tears.
3 . keep somebody ↔ back to prevent someone from being as successful as they could be SYN hold back :
Fear and stereotypes have kept women back for centuries.
4 . keep something ↔ back especially British English to not give or pay something that you were going to give:
They kept back some of his wages to pay for the damage.