buttoned up, clammed up, close, close-mouthed, could hear a pin drop, dumb, hushed, hushful, inaudible, low, low-pitched, muffled, mute, muted, noiseless, not saying boo, peaceful, quiescent, quieted, reserved, reticent, secretive, silent, soft, soundless, speechless, still, stilled, taciturn, tight-lipped, uncommunicative, unexpressed, unspeaking, unuttered, whist
calm, cessation, dead air, ease, hush, lull, noiselessness, peace, quietness, quietude, relaxation, repose, rest, serenity, soundlessness, speechlessness, still, stillness, stop, termination, tranquillity
calmness, dispassion, doldrums, hush, impassivity, imperturbation, lull, patience, peace, peace of mind, peacefulness, placidity, quiet , repose, rest, restraint, serenity, silence, stillness, stoicism, tranquility