dumb adj.
1 unable to speak
VERBS be | become, be struck They were struck dumb by some sort of shock.
PREP. with She sat there, dumb with rage.
PHRASES deaf and dumb
2 stupid
VERBS be, feel, look, seem, sound I'm sure my question sounded really dumb. | act, play I decided to act dumb.
ADV. really, very | pretty, rather
You can also check other dicts: dumb (English, 中文解释 ), wordnet sense, Collins Definition