- An informer; stool pigeon.
- A worker who is a scab.
- A person who deserts or betrays a cause.
A rink rat.
A gym rat, a mall rat.
Ratted on his best friend to the police.
His comrades will not rat him out.
An example of a rat is a roof rat.
An example of a rat is a person who plays mean tricks on his coworkers.
An example of rat is to poof the front of the hair.
An example of rat is for a cat to hunt for rats.
An example of rat is to tattle on a friend.