silent as the grave
Saying absolutely nothing (especially about a particular subject).
The investigation is ongoing, but all the suspects have been silent as the grave so far.
VERBS
be, seem
become, fall, go, grow
The music stopped and the classroom went silent as everyone waited for the test to begin.
keep, lie, remain, sit, stand, stay
The audience remained silent as the magician performed his most difficult trick.
ADV
remarkably, unusually | absolutely, completely, perfectly, quite, totally, utterly
almost, virtually
The library was almost silent except for the soft sound of pages turning.
largely
The government remained largely silent on the causes of the economic crisis.
fairly, rather | suddenly
eerily, strangely
The old house felt eerily silent after everyone had left for the day.
grimly, obstinately, resolutely, stubbornly
The teenager sat stubbornly silent throughout the entire family dinner.
uncomfortably
The two old friends sat uncomfortably silent at the dinner table, avoiding each other's eyes.
uncharacteristically
PREP
about
My parents remained silent about the reasons for their divorce until I was older.
on
The government remained silent on the controversial issue throughout the election campaign.