brainless (adj.)
- apish
- asinine
- batty
- beguiled
- besotted
- buffoonish
- cockeyed
- crazy
- credulous
- daft
- dazed
- dizzy
- doting
- dumb
- empty-headed
- fatuous
- featherbrained
- flaky
- fond
- foolish
- frivolous
- fuddled
- futile
- gaga
- giddy
- goofy
- harebrained
- headless
- idiotic
- ignorant
- imbecile
- inane
- inept
- infatuated
- insane
- insensate
- irrational
- kooky
- loony
- mad
- maudlin
- mindless
- moronic
- nitwitted
- nutty
- rattlebrained
- rattlepated
- reasonless
- sappy
- scatterbrained
- screwy
- senseless
- sentimental
- silly
- stupid
- thoughtless
- unintelligent
- unreasoning
- untalented
- unthinking
- unwise
- wacky
- wet
- witless
