Idiom meaning someone suddenly becomes quiet, meek, or well-behaved (as if they were a borrowed cat); often used as 'like a borrowed cat'.
普段は元気な彼女が、面接中は借りてきた猫のように静かだった。
She, who is usually lively, was as quiet as a borrowed cat during the interview.
子どもたちは先生が来ると借りてきた猫みたいにおとなしくなる。
The children become quiet like borrowed cats when the teacher arrives.
彼は緊張していて、パーティー中ずっと借りてきた猫の状態だった。
He was nervous and remained like a borrowed cat throughout the party.