See speechless in Webster's New World Roget's A-Z Thesaurus II
adjective
Lacking the power or faculty of speech:
aphonic, dumb, inarticulate, mute, voiceless. See wordsTemporarily unable or unwilling to speak, as from shock or fear:
dumb, inarticulate, mum, mute, silent, voiceless, wordless. See words
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