brainless

Adjective

brainless (comparative more brainless, superlative most brainless)

1. (not comparable) Having no brain.
   • Surely it was more likely that a brainless creature, acting solely by vague predatory instinct, would give up the chase when I disappeared, and, after a pause of astonishment, would wander away in search of some other prey?1912, Arthur Conan Doyle, The Lost World […], London; New York, N.Y.: Hodder and Stoughton, →OCLC

   Synonyms:

   anencephalous

2. (comparable) Unintelligent, with little common sense.
   • "I don't mean all of your friends—only a small proportion—which, however, connects your circle with that deadly, idle, brainless bunch—the insolent chatterers at the opera, the gorged dowagers, the worn-out, passionless men, the enervated matrons of the summer capital,[…]!"1907 August, Robert W[illiam] Chambers, chapter VI, in The Younger Set, New York, N.Y.: D. Appleton & Company, →OCLC

   Synonyms:

   half-brained, half-witted, addlebrained, addlepated, airheaded, bee-brained, beef-witted, soft, beefheaded, beetle-headed

   Antonyms:

   brainy

3. Of an action performed, overly repetitive and unchallenging, not requiring any careful attention or providing any significant stimulation.
   • Near-synonyms: automatic, rote, dull

   Synonyms:

   mindless, automatic, rote, dull

   Antonyms:

   engrossing