word of mouth

all mouth and no trousers

Alternative form of all mouth and trousers.

all mouth and trousers

Superficial, engaging in empty, boastful talk, but not of real substance.

all one's taste is in one's mouth

One lacks good taste in aesthetic or cultural matters.

bad taste in one's mouth

A feeling that something is morally despicable as to cause nausea.

bad word

A vulgar word.

big mouth

The mouth of someone who talks too much, especially by making exaggerated claims or by inappropriately revealing information.

born with a silver spoon in one's mouth

Born rich, or into a wealthy family.

breathe a word

To divulge even part of a secret (usually used with a negative).