<p><strong>Adjective</strong></p><ul><li>lacking intelligence or good judgment; stupid; dull-witted</li><li>lacking the power of speech (offensive when applied to humans): a dumb animal</li><li>temporarily unable to speak: dumb with astonishment</li><li>refraining from any or much speech; silent</li><li>made, done, etc., without speech</li><li>lacking some usual property, characteristic, etc.</li><li>performed in pantomime; mimed</li><li>pertaining to the inability to do processing locally</li></ul><p><strong>Verb Phrase</strong></p><ul><li>Informal. to make or become less intellectual, simpler, or less sophisticated: to dumb down a textbook; American movies have dumbed down.</li></ul>