not open (one's) mouth

(redirected from not 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 classic literature ?
Those fellows up there did not open their mouths, and were so stupid that they let the few old rags which they had on their bodies get burnt.
While a few people knew the selections from memory, others sat with their eyes closed just listening, and still others stood during the chorus numbers but did not open their mouths.
Spare me the mewling about "ordered liberty," please--50 years of conservative pieties about "ordered liberty" led to Dick Cheney and a movement full of "men" who dared not open their mouths to defend liberty when she needed it most.
Or members of the present Cabinet who dare not open their mouths without permission?