Мы в Telegram на канале Учим Английский
heart in one's mouth
Ощущение великого страха или нервозности. — Часто считается избитой фразой.
Charles got up to make his first speech with his heart in his mouth.
My heart was in my mouth as I went into the haunted house.
When the bear came out of the woods towards us, our hearts were in our mouths.
Ср.: HAIR STAND ON END.
Источник: A Dictionary of American Idioms