vacuous

UK: /ˈvækjʊəs/ US: /ˈvækjuəs/ ,(vak′yo̅o̅ əs)

WordReference Random House Learner's Dictionary of American English © 2026

vac•u•ous /ˈvækyuəs/   adj. 

1. lacking contents;
   empty.
2. lacking in ideas or intelligence:
   a vacuous mind; a vacuous smile.

vac•u•ous•ly, adv. See -vac-.

WordReference Random House Unabridged Dictionary of American English © 2026

vac•u•ous  (vak′yo̅o̅ əs), adj. 

1. without contents;
   empty:
   the vacuous air.
2. lacking in ideas or intelligence:
   a vacuous mind.
3. expressing or characterized by a lack of ideas or intelligence;
   inane;
   stupid:
   a vacuous book.
4. purposeless;
   idle:
   a vacuous way of life.

• Latin vacuus empty; see -ous
• 1645–55

vac′u•ous•ly, adv. 
vac′u•ous•ness, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

vacuous / ˈvækjʊəs/ adjective

1. containing nothing; empty
2. bereft of ideas or intelligence; mindless
3. characterized by or resulting from vacancy of mind: a vacuous gaze
4. indulging in no useful mental or physical activity; idle
5. (of an operator or expression) having no import; idle: in (x) (John is tall) the quantifier (x) is vacuous

Etymology: 17th Century: from Latin vacuus empty, from vacāre to be empty

ˈvacuously adverb