origionally the term 'hoodrat' was meant to describe someone that walks around with a bad attitude commiting crimes, useually in baggy clothing wearing a tracksuit with a hooded top (hence why the term is hoodrat0. but lately people have started useing it to generalise the people in hooded tops and baggy clothing
From what I've heard, "hood rat" is a term used to describe a girl who exhibits a trashy demeanor. Someone who hangs out with a lot of guys in a neighborhood, who people really don't think much of.
It's definitely not a good thing.
I believe a "hood rat" is a person that lives in a "ghetto" and acts "ghetto". It's not usually percieved as a good thing. But it's just a stereotype and shouldn't be taken seriously anyways.
A hood rat is a person to acts ghetto and talk ghetto. Like those certain females that act extremely loud and obnoxious talking in slang starting trouble.
Zoe explained it almost perfectly :]