English Idioms: Watch one’s mouth

English Idioms About “Parts of the body”
Idiom: Watch one’s mouth
Meaning: To be careful about what one says, especially with regard to disrespectful or profane language.
Example: Watch your mouth when you speak to him. He’s the boss.

English Idioms: Loose cannon

English Idioms About “War”
Idiom: Loose cannon
Meaning: The idiom “loose cannon” refers to a person who is unpredictable or uncontrolled and who is likely to cause unintentional damage.
Example: He is considered a loose cannon because he is unable to control himself.