From Longman Dictionary of Contemporary Englishhold out on somebody phrasal verb informalTELL A SECRETto not tell someone about something important She must have been holding out on him all these years. → hold→ See Verb table
Examples from the Corpus
hold out on • Harry would know that his brother was holding out on him, as he always did.• Now, I suppose I regret holding out on him.• They are holding out on me.• Mrs Sweet was holding out on the police.• They must think we're holding out on them.