She smiled demurely at the teacher — butter will not melt in someone's mouth — yet she had clearly cheated on the exam.

He used the phrase one's heart in one's mouth to describe how he felt during the crash.

When you're in a tense negotiation, remember that a closed mouth catches no flies; sometimes silence protects you more than words.

If one gets nervous, it's easy to run off one's mouth and say something you'll regret.

For someone who had publicly denounced the policy for years, praising it now would lie ill in one's mouth.

If one accidentally eats the wild berries, it's wise to wash out one's mouth immediately with clean water.

Growing up, her mother insisted that washing one's mouth out with soap was the only punishment for swearing.

The clinic reported several cases of hand-foot-mouth disease among preschoolers this week.

The pediatrician explained that hand, foot, and mouth disease is highly contagious among toddlers.

It's unwise to shoot off one's mouth when you don't know the whole story.