rat

The rat scurried into the hole.

ネズミが穴に走り込んだ。

He was called a rat for betraying his friends.

彼は友人を裏切ったことで裏切り者と呼ばれた。

He decided to rat on his accomplices.

彼は共犯者を密告することに決めた。

He ratted his friend out to the police.

彼は友人を警察に密告した。