Synonyms for Fatuous:

adj.

foolish (adjective)
witless.
senseless (adjective)
silly.
stupid (adjective)
asinine, brainless, foolish, idiotic, inane, insensate, mindless, silly, vacuous, witless.
thoughtless (adjective)
blank, brainless, empty-headed, illogical, inane, mindless, thoughtless, unoccupied, unreasonable, unthinking, unthoughtful, vacant, vacuous.

n.

childish, extreme, hysterical, idiotic, irrational, irresponsible, perverse, ridiculous, silly, wrong, study at silly. ability, insensate, planned, unintelligent, witless, Weak-minded. fatuous (noun)
asinine, foolish, inane, mindless, vacuous.

Other synonyms:

witless. idiotic, unintelligent, Weak-minded. insensate. Other relevant words:
ability, asinine, childish, extreme, foolish, hysterical, idiotic, insensate, irrational, irresponsible, perverse, planned, ridiculous, silly, unintelligent, witless, wrong, Weak-minded.

Usage examples for fatuous

  1. Yes, Tobie replied, with a fatuous air, an excellent sort of man; but I know his wife much better. – San-Cravate; or, The Messengers; Little Streams by Charles Paul de Kock
  2. His opportunity came in 1853, when conservatives and clericals indulged the fatuous hope that he would both sustain their privileges and lift Mexico out of its sore distress. – The Hispanic Nations of the New World Volume 50 in The Chronicles Of America Series by William R. Shepherd
  3. And his passing mastery over her was gone too- he smiled to remember that, hardly two hours earlier, he had been fatuous enough to think he could still regain it! – The Fruit of the Tree by Edith Wharton