| impregnable(adjective, secure, safe, snug, intact) |
| in chambers(expression, mysterious, private, reticent, taciturn) |
| in privacy(expression, mysterious, private, reticent, taciturn) |
| in private(expression, mysterious, private, reticent, taciturn) |
| in safety(expression, adjective, secure, safe, snug) |
| in the background(expression, idiom, mysterious, reticent, taciturn) |
| in the dark(expression, idiom, mysterious, reticent, taciturn) |
| inarticulate(quiet, soft, still, silent, dazed) |
| inaudible(adjective, close, quiet, soft, low) |
| incoherent(quiet, soft, still, silent, hushed) |
| inconversable(adjective, close, quiet, soft, restrained) |
| indistinct(quiet, soft, still, silent, hushed) |
| inert(adjective, calm, quiet, smooth, tranquil) |
| inhibited(quiet, soft, still, silent, hushed) |
| inobtrusive(adjective, quiet, soft, low, silenced) |
| intact(adjective, secure, safe, snug, sheltered) |
| inviolable(adjective, secure, safe, snug, intact) |
| invulnerable(adjective, secure, safe, snug, intact) |
| laconic(quiet, soft, still, silent, hushed) |
| lifeless(adjective, calm, quiet, smooth, tranquil) |