#1 quieten v. [hush, quiet, quiesce, quiet down, pipe down] become quiet or quieter; "The audience fell silent when the speaker entered". wn
#2 quieten v. [calm, calm down, quiet, tranquilize, tranquillize, tranquillise, lull, still] make calm or still; "quiet the dragons of worry and fear". wn
#3 quieten v. [hush, silence, still, shut up, hush up] cause to be quiet or not talk; "Please silence the children in the church!". wn
vizzz