To tell off is to speak angrily to somebody about their behaviour. Tell him off, get told off, a good telling off.
It is what an adult does to a child or a manager to a junior, so it runs downhill. It is spoken rather than written and does not survive into a letter.
1phrasetell offTo speak angrily to somebody about their behaviour.
“The caretaker would tell off anybody who cycled through the yard.”
tell off is a phrase.
Practised in Phrasal Verbs