Dumb/dʌm/ Definition 1 of 4Pro Tip 1/2Literal Silence Originally meant unable to speak, used for physical inability to vocalize. In the past, people who were deaf were often called dumb too. Pro Tip 2/2Sensitive Usage Be careful using 'dumb' to describe non-speaking; it may be offensive. Instead of 'dumb', it's more respectful to say 'non-verbal'.