1. To speak to (someone) roughly about something he did wrong; blame; scold.
Mrs. Thompson got on the girls for not keeping their rooms clean.
The fans got on the new shortstop after he made several errors.
Syn.: JUMP ON.
2. See: GET ALONG.
3. To grow older.
Work seems harder these days; I'm getting on, you know.
Source: A Dictionary of American Idioms