1.
( informal ) to know about what sb has done wrong :
She knew the police would be onto them.
2.
to be talking to sb, usually in order to ask or tell them sth :
They've been onto me for ages to get a job.
1.
( informal ) to know about what sb has done wrong :
She knew the police would be onto them.
2.
to be talking to sb, usually in order to ask or tell them sth :
They've been onto me for ages to get a job.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005