simple past tense and past participle of suppress
"The manager suppressed the employee's complaints before they could reach the board."
kept from public knowledge by various means
"The investigation revealed that several key witnesses had been suppressed to prevent the public from learning about the cover-up."
held in check with difficulty
"a smothered cough"
"a stifled yawn"
"a strangled scream"
"suppressed laughter"