Dumb synonyms such as blockish, at a loss for words, aphasic, as thick as two short planks, and birdbrained. Dumb is an adjective, and its antonyms are smart and intelligent. Additionally, here are 75 synonyms for dumb and words similar to it.
At a loss for words, close-mouthed, inarticulate, mum, saying nothing, silent, speechless, taciturn, tight-lipped, tongue-tied, uncommunicative, untalkative, voiceless, and wordless.
Aphasic, aphonic, dumb, mute, unable to speak, and without the power of speech.
As thick as two short planks, birdbrained, blockish, boneheaded, bovine, brain-dead, brainless, chuckleheaded, cretinous, daft, dead from the neck up, dense, dim, dippy, dof, doltish, dopey, dotish, dozy, dull, dull-witted, dunce-like, dunderheaded, empty-headed, fat-headed, foolish, half-baked, half-witted, idiotic, ignorant, imbecilic, lamebrained, lumpish, mindless, moronic, muttonheaded, not the full shilling, obtuse, pea-brained, simple, simple-minded, slow, slow on the uptake, slow-witted, soft in the head, stupid, thick, thick-skulled, thickheaded, unintelligent, vacuous, vapid, witless, and wooden-headed.