tell off
To castigate, rebuke, or reprimand one in a severe or merciless manner. A noun or pronoun can be used between "tell" and "off." It's about time someone told Jim off for his lewd behavior in the office. The waiter told off the rude customer for acting so inappropriately towards her.
tell someone off
to scold someone; to attack someone verbally. (This has a sense of finality about it.) I was so mad at Bob that I told him off. By the end of the day, I had told off everyone else, too.
tell off
Rebuke severely, reprimand, as in It's time someone told her off about her behavior. There is also a synonymous expression, tell someone where to get off, as in When he called back a third time, I told him where to get off. [Colloquial; early 1900s] Also see get off, def. 7.
tell off
v. To reprimand someone or something; rebuke someone or something: The customer told off the rude clerk. I was so mad at my roommate for forgetting to pay the rent each month that I finally told him off.