vacuous

该批评空洞无物，没有任何实质性贡献。

The criticism is ___vacuous and contributes nothing substantive.

那场名人访谈全是关于时尚和派对的空洞闲聊。

The celebrity interview revealed only ___vacuous chatter about fashion and parties.

他问路时店员给了他一个空洞茫然的眼神，显然根本没理解他的问题。

The clerk gave him a ___vacuous look when he asked for directions, clearly not processing the question.