have a quiet word (with somebody)
From Longman Dictionary of Contemporary Englishhave a quiet word (with somebody)have a quiet word (with somebody)especially British EnglishPRIVATE/PERSONAL to talk to someone privately when you want to criticize them or tell them about something serious Brian’s just not keeping up with the workload. Can you have a quiet word? → quietExamples from the Corpushave a quiet word (with somebody)• When all they needed to do was lift up the phone and have a quiet word.