| peaceable |
| quiet speechless(expression, still, hushed, soundless) |
| quieted(adjective, close, quiet, soft, low) |
| reserved(adjective, close, quiet, soft, low) |
| reticent(adjective, close, quiet, soft, low) |
| sealed(adjective, calm, quiet, smooth, tranquil) |
| secretive(adjective, close, quiet, soft, low) |
| silentious(still, hushed, soundless) |
| smooth(adjective, calm, quiet, tranquil, silent) |
| stable(adjective, calm, quiet, smooth, tranquil) |
| stagnant(adjective, calm, quiet, smooth, tranquil) |
| static(adjective, calm, quiet, smooth, tranquil) |
| stationary(adjective, calm, quiet, smooth, tranquil) |
| still as death(expression, idiom) |
| stilled(adjective, close, quiet, soft, low) |
| stock-still(adjective, calm, quiet, smooth, tranquil) |
| struck dumb(expression, still, hushed, soundless) |
| subaudible |
| tacit |
| taciturn(adjective, close, quiet, soft, low) |