List of silent synonyms and silent related words.
aphonic, brief, brusque, calm, checked, close, close-lipped, close-tongued, closemouthed, concise, curbed, curt, dumb, echoless, economical of words, hush as death, hushed, implicit, implied, inactive, inarticulate, inaudible, incoherent, indisposed to talk, inhibited, laconic, mousy, mum, mute, muted, noiseless, pacific, passive, peaceful, placid, quiescent, quiet, reserved, restrained, reticent, secretive, serene, short, sleeping, snug, soundless, sparing of words, speechless, still, still as death, stilly, subaudible, tacit, taciturn, terse, tight-lipped, tongue-tied, tranquil, unagitated, unarticulated, uncommunicative, undeclared, understood, undisturbed, unexpressed, unhearable, unloquacious, unmentioned, unproclaimed, unpronounced, unpublished, unrecorded, unruffled, unsaid, unsociable, unsounded, unspoken, unstated, unsung, untalkative, untalked-of, untold, untroubled, unuttered, unvocalized, unvoiced, unwritten, voiceless, whist, word-bound, wordless