Brainless

Origin

brain + -less

Full definition of brainless

Adjective

1. (not comparable) Having no brain.
2. (comparable) Unintelligent, with little common sense.
• 1907, w, The Younger Set Chapter 6, “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, … !”