adj. dumb·er,
dumb·est 1. a. Lacking the power of speech. Used of animals and inanimate objects.
b. Offensive Incapable of using speech; mute. Used of humans. See Usage Note at
mute.
2. Temporarily speechless, as with shock or fear: I was dumb with disbelief.
3. Unwilling to speak; taciturn.
4. Not expressed or articulated in sounds or words: dumb resentment.
5. Nautical Not self-propelling.
6. Conspicuously unintelligent; stupid: dumb officials; a dumb decision.
7. Unintentional; haphazard: dumb luck.