hold back (something)
— phrasal verb with hold us/hoʊld/verb past tense and past participle held /held/
to stop something from happening or advancing, or to keep someone from doing something:
She held back from interfering in their arguments.
Sandbags will hold back the flood waters for a while.
He admitted that something had gone wrong, but he held back the details (= stopped himself from telling the complete truth).