A person who constantly gets in trouble by breaking the law, lying,
cheating or slacking off and expects everyone around them to take the blame for those offenses. A rat usually gets away with it by accusing others of offenses to
push blame off of themselves (these are usually
lies).
A rat
will also take credit for anything positive, such as the hard work and accomplishments of others and when they get caught they are the first to call others a rat in order to place blame on others.
A rat never takes the blame for his/her actions, and they
will fight tooth and nail to prove their innocence and escape justice.
A rat pollutes the neighborhood, workplace or any other environment, making it unlivable for others.
Jo: Look at all the work I did, this place is spotless!
Lila: You sat on you ass all
day and
left trash everywhere! This place is a rat's nest.
Jo: You effing RAT!