| muffled(adjective, quiet, soft, low) |
| muted(adjective, calm, quiet, soft, gentle) |
| noiseless(adjective, quiet, soft, low) |
| not saying boo(expression, adjective, idiom, quiet, soft) |
| on a leash(expression, idiom, calm, quiet, reasonable) |
| plain(adjective, calm, quiet, reasonable, mild) |
| quieted(adjective, quiet, soft, low, silenced) |
| reasonable(adjective, calm, quiet, mild, subdued) |
| retiring(calm, quiet, reasonable, mild, controlled) |
| self-controlled(adjective, calm, quiet, reasonable, mild) |
| shrinking(adjective, calm, quiet, reasonable, mild) |
| soundless(adjective, quiet, soft, low) |
| steady(adjective, calm, quiet, reasonable, mild) |
| stilled(adjective, quiet, soft, low, silenced) |
| temperate(calm, quiet, reasonable, mild, controlled) |
| tight-lipped(adjective, quiet, soft, low) |
| unaffable(adjective, calm, quiet, reasonable, mild) |
| uncommunicative(adjective, quiet, soft, low) |
| undemonstrative(calm, quiet, reasonable, mild, controlled) |
| under control(expression, adjective, calm, quiet, reasonable) |