1
general::
Talk loudly and vehemently, especially in anger, as in There you go again, ranting and raving about the neighbor's car in your driveway. This idiom is a redundancy, since rant and rave mean just about the same thing, but probably survives on account of its alliterative appeal. In addition to the idiom beginning with RAP, Also see BEAT THE RAP; BUM RAP; NOT GIVE A DAMN (RAP); TAKE THE RAP.
American Heritage Idioms
2
general::
Phrase(s): rant and rave (about someone or something)
to shout angrily and wildly about someone or something. • Barbara rants and raves when her children don’t obey her. • Bob rants and raves about anything that displeases him.
McGrawhill's American Idioms And Phrasal Verbs