Synonyms and related words :
Greek to one, ambiguous, anaudic, aphasic, aphonic, bashful, beyond understanding, blurred, breathless, breathy, choked, choking, confused, conscious, coy, croaking, demure, digressive, discursive, disjointed, drawling, drawly, dumb, dumbfounded, dumbstricken, dumbstruck, dysphonic, faltering, garbled, guttural, halting, harsh, hawking, hesitating, hoarse, illogical, impenetrable, implicit, implied, incognizable, incoherent, incomprehensible, indistinct, inferred, inscrutable, irrational, jumbled, lisping, maundering, mispronounced, mixed-up, mousy, muddled, muffled, mum, mumbled, mumbling, mute, muzzy, nasal, numinous, past comprehension, quavering, rambling, scrambled, self-conscious, shaking, shaky, shamefaced, shamefast, shy, silent, skittish, snuffling, speechless, stammering, stifled, strangled, stricken dumb, thick, throaty, timid, timorous, tongue-tied, tongueless, tremulous, twangy, unclear, unconnected, undeclared, unexpressed, unfathomable, unintelligible, unknowable, unsaid, unsearchable, unspoken, unuttered, velar, voiceless, wild, wordless