(someone had) better keep quiet about it

(someone had) better keep quiet about it

(Someone had) better not say anything about a particular issue or situation. "Someone" can be used in the phrase itself, especially when the listener already knows who the speaker is talking about. A: "I think Jake knows that we doctored the numbers in that report." B: "Well, someone had better keep quiet about it then." Better keep quiet about it so that the boss doesn't suspect anything.
See also: better, keep, quiet
Farlex Dictionary of Idioms.
See also:
  • (someone had) better keep still about it
  • Better keep still about it
  • (I'm) just saying
  • Will I see you again?
  • FWIW
  • IJS
  • 57
  • (one's) best foot forward
  • (as) sure as eggs (is eggs)
  • I don't suppose