| buttoned up(expression, adjective, close, quiet, smooth) |
| clammed up(expression, adjective, close, quiet, smooth) |
| close(adjective, quiet, soft, peaceful) |
| close-mouthed(adjective, close, quiet, smooth, soft) |
| could hear a pin drop(expression, adjective, idiom, close, quiet) |
| dumb(adjective, close, quiet, soft) |
| hushed(adjective, close, quiet, smooth, soft) |
| inaudible(adjective, close, quiet, soft) |
| inobtrusive(adjective, quiet, soft, silenced) |
| low-pitched(adjective, close, quiet, soft) |
| muffled(adjective, close, quiet, soft) |
| mute(adjective, close, quiet, soft) |
| muted(adjective, close, quiet, soft) |
| noiseless(adjective, close, quiet, smooth, soft) |
| not saying boo(expression, adjective, idiom, close, quiet) |
| quiescent(adjective, close, quiet, soft) |
| quiet(adjective, calm, close, smooth, soft) |
| quieted(adjective, close, quiet, soft) |
| reserved(adjective, close, quiet, soft) |
| reticent(adjective, close, quiet, soft) |