| taciturn(quiet, restrained, still, reticent, discreet) |
| tight-lipped(quiet, restrained, reticent, discreet, closemouthed) |
| tongue-tied(still, hushed, soundless) |
| unclear(still, hushed, soundless) |
| uncommunicative(quiet, restrained, still, reticent, discreet) |
| unforthcoming(quiet, restrained, reticent, discreet, tight-lipped) |
| unheard(still, hushed, soundless) |
| unsociable(still, hushed, soundless) |
| unspeaking(adjective, close, quiet, restrained, still) |
| voiceless(still, hushed, soundless) |
| wordless(adjective, close, quiet, restrained, still) |
| zipped(still, hushed, soundless) |
| be calm(quiet, inactivate) |
| cagey(quiet, restrained, discreet) |
| can it(expression, quiet, inactivate) |
| choke off(expression, quieten, shush, dulling) |
| close-mouthed(quiet, restrained, discreet) |
| close up(expression, quieten, shush, dulling) |
| confidentiality(adjective, hushed, wordless) |
| cool it(expression, quiet, quieten, inactivate, shush) |