n. 25B6; adjective
she stood dumb while he shouted : MUTE, speechless, tongue-tied, silent, at a loss for words; taciturn, uncommunicative, untalkative, tight-lipped, close-mouthed; informal mum.
(informal) he is not as dumb as you'd think : STUPID, unintelligent, ignorant, dense, brainless, mindless, foolish, slow, dull, simple, empty-headed, vacuous, vapid, idiotic, half-baked, imbecilic, bovine; informal thick, dim, moronic, cretinous, dopey, dozy, thickheaded, wooden-headed, fat-headed, birdbrained, pea-brained; Brit. informal daft.
clever.