keeping back
phrasal verbUK /ˌkiːpɪŋ ˈbæk/
US /ˌkiːpɪŋ ˈbæk/
Holding something so it does not move forward or go away.
The teacher was keeping back the excited kids until the bell rang.
OTHER MEANINGS
2. Not telling someone something you know.
She was keeping back the surprise until his birthday.
3. Saving something for later instead of using it now.
He is keeping back some money for a rainy day.
4. Making a student stay after class as a punishment.
The coach was keeping back the players who missed practice.
5. Stopping something from getting closer or reaching you.
The wall was keeping back the flood water.