not say a word
not breathe a word

And he hadn't breathed a word of it at home.

I haven't breathed a word of this to anyone else.

Who's going to breathe a word about them around you?

Don't ever breathe a word to anyone about having known him.

If he did, he'd not have breathed a word of it to me.

It is well understood that he did not breathe a word about the other.

Don't breathe a word to anyone about my having anything to do with it.

And never breathe a word of how I've taken a hand in politics here.

And I don't want anyone to breathe a word about this.

Haven't even breathed a word of it to anyone but you.