vac·u·ous
adjective/ˈvækjuəs/
/ˈvækjuəs/
(formal)- showing no sign of intelligence or sensitive feelings
空洞的；空洞无物的 - a vacuous expression
茫然的表情
Word Originmid 17th cent. (in the sense ‘empty of matter’): from Latin vacuus ‘empty’ + -ous. - a vacuous expression