1. 思想贫乏的;空洞的;无知的
If you describe a person or their comments as vacuous, you are critical of them because they lack intelligent thought or ideas.

1. void of expression

e.g. a blank stare

Synonym: blank

2. devoid of matter

e.g. a vacuous space

3. devoid of significance or point

e.g. empty promises
a hollow victory
vacuous comments

Synonym: emptyhollow

4. devoid of intelligence

Synonym: asininefatuousinanemindless