| secluded(adjective, quiet, reserved, secret, private) |
| sententious(aloof, reserved, reticent, uncommunicative) |
| snug |
| soft(adjective, close, quiet, low, peaceful) |
| soundless(adjective, close, quiet, soft, low) |
| sparing(aloof, reserved, reticent, uncommunicative) |
| sparing of words(expression, idiom) |
| still(adjective, close, quiet, soft, low) |
| stilled(adjective, close, quiet, soft, low) |
| surreptitious |
| terse |
| tight chops(expression, adjective, quiet, reserved, secret) |
| un-talkative(adjective, taciturn) |
| undercover(mysterious, private, reticent, taciturn, uncommunicative) |
| unexpressed(adjective, close, quiet, soft, low) |
| unexpressive(aloof, reserved, reticent, uncommunicative) |
| unloquacious |
| unresponsive(adjective, reserved, reticent, taciturn) |
| unsociable(quiet, shy, reserved, reticent, silent) |
| unspeaking(adjective, close, quiet, soft, low) |