not open (one's) mouth

(redirected from open their mouths)

not open (one's) mouth

To be completely silent; to remain discreet (about something); to not tell anyone (about something). All the while our teacher was shouting at us, we didn't open our mouths. Don't open your mouth about this! I would die of embarrassment if anyone were to find out.
See also: mouth, not, open

not open one's mouth

 and not utter a word
Fig. not to say anything at all; not to tell something (to anyone). Don't worry, I'll keep your secret. I won't even open my mouth. Have no fear. I won't utter a word.
See also: mouth, not, open

not open one's mouth

Also, shut one's mouth; not say or utter a word . Be silent, repress one's feelings or opinions, keep a secret. For example, Don't worry, I'm not going to open my mouth on this issue, or She promised not to say a word about it to anyone. Also see hold one's tongue; keep one's mouth shut.
See also: mouth, not, open

open your (big) ˈmouth

(informal) say something when you should not: Why do you always have to open your big mouth? Can’t you just keep quiet sometimes?
See also: mouth, open
References in periodicals archive ?
Researchers were able to make 9 of the unconscious patients bring their hands up and open their mouths by stimulating a part of the brain that is linked to those actions in non-human primates.
WOULD it be possible to display subtitles when Am-I-Will and Jessie J open their mouths on The Voice?
We are all for honesty in politics but ministers have a responsibility to think before they open their mouths.
THERE are some people who, each time they open their mouths, seem to put their foot in it.
Animals can be trained to open their mouths to let us brush their teeth," says Dr.
When Idol contestants open their mouths to sing, the audience hears the sounds produced by air moving through the singer's voice box, or larynx.
When they're out foraging and find a seed, they simply open their mouths and tuck it in.
Eventually, "the skin of the cheek becomes hard as a brick," and people with the condition become unable to open their mouths, says Sylvie-Louise Avon of Laval University in Quebec City.
Seeing these superb comic actors again in yet another sharply written satire is enough to make you smile before they even open their mouths.
They're there behind the scenes to administer hugs as hopefuls are given the thumbs up or the heartbreaking news that they're rubbish and should never dare open their mouths again.
A seventh grader interviewed by a reporter said that after they were made to take off their clothes, he and his classmates were told to open their mouths and bend over.
Wall Street analysts need only open their mouths to draw attention.
But the women don't need to throw open their mouths distractingly in order to express feeling.
Now, a new study, led by Per Christiansen, from Aalborg University in Denmark, has revealed that the cats' jaw muscles evolved into a specialised pattern, which allowed them to open their mouths so wide.
Next time Fern (left) and her husband open their mouths, they should think about what's coming out of them - not just what's going in