tell on (third-person singular simple present tells on, present participle telling on, simple past and past participle told on)
- To inform on; to tattle; to tell someone with authority that someone else has done something wrong; usually somewhat childish.
- My sister told on me when I didn't go to school.
- Bible, 1 Sam. xxvii. 11
- Lest they should tell on us, saying, So did David.
- To cause visible strain to somebody or something.
- Years of drinking started to tell on his body.
to tell someone that someone else has done something wrong