a long-tailed animal related to but larger than the mouse
a worthless disloyal person
break an agreement, a promise, etc.; fail to do sth one has undertaken to do; betray sb
"only a rotter would do that"
"kill the rat"
"throw the bum out"
"you cowardly little pukes!"
"the British call a contemptible person a `git'"
"He told on his classmate who had cheated on the exam"
When the rat protested that he loved Sal, she chucked a drink in his face.
Witnesses..ratting on former colleagues.
He's a solicitor who's ratted on a client! He could be struck off for that, you know!
出自： K. Lette
The police know we're here.Someone must have ratted on us.
We shouldn't rat on our promise.