keeps one trap shut (verb) button one's lip: keep silent
Sinonime: admiring,
appreciative,
civil,
considerate, courtly, deferential, duteous, dutiful,
gracious,
humble,
obedient, obeisant,
polite, recognizing, regardful, regarding, reverent, reverential, self-effacing,
solicitous,
submissive, upholding, venerating, well-mannered
Antonime: discourteous,
mean, unmannerly