be on about something

be ˈon about something

(informal) talk about something; mean something: I didn’t know what he was on about. It didn’t make sense.
See also: on, something

be/go/keep ˈon about something

(informal, disapproving) keep talking about the same thing so that people become bored or annoyed: What’s she on about now?Don’t keep on about your terrible journey. It’s so boring.
See also: keep, on, something