[yǎ kǒu wú yán]
be rendered speechless; be dumbfounded; be left without an argument; be put down; be reduced to silence; be struck dumb; be stumped; (He) closed (his) mouth and had nothing to say.; have nothing to say for oneself; inarticulate; keep mute as a maggot; keep silent; put to silence; shut up when defeated in an argument; strike dumb; There is nothing more one can say.; tongue-tied
His forceful arguments silenced his opponent.
他论辩有力， 把对方说得哑口无言。