2) A person who complains excessively.
3) A person, place or thing that is getting on your nerves.
guy1: Hey, did you go home with that chick on her period last night?
guy2: Hell yea, I fucked that ragger raw!
I can't come out to the party tonight, my parents are being such raggers and grounded me.
Ragging, being ragger or rag all refer to this and is frowned upon by the rich.