| mousy(quiet, soft, still, silent, hushed) |
| muffled(adjective, close, quiet, soft, low) |
| mum(adjective, quiet, soft, restrained, aloof) |
| muted(adjective, close, quiet, soft, low) |
| nonvocal(adjective, close, quiet, soft, restrained) |
| not forthcoming(expression, quiet, shy, silent, tight-lipped) |
| not saying boo(expression, adjective, idiom, close, quiet) |
| not talkative(expression, adjective, close, quiet, restrained) |
| on the QT(expression, idiom, reserved, reticent, taciturn) |
| pacific(adjective, calm, quiet, smooth, tranquil) |
| placid(adjective, calm, quiet, smooth, tranquil) |
| quiescent(adjective, close, quiet, soft, low) |
| quiet speechless(expression, still, hushed, soundless) |
| quieted(adjective, close, quiet, soft, low) |
| restful(adjective, calm, quiet, smooth, tranquil) |
| restrained(quiet, soft, low, careful, reticent) |
| sealed(adjective, calm, quiet, smooth, tranquil) |
| secretive(adjective, close, quiet, soft, low) |
| sententious(aloof, reserved, reticent, uncommunicative) |
| serene(adjective, calm, quiet, smooth, tranquil) |