adjective
- having or showing a lack of good sense; foolish or crazy
Usage: informal; somewhat dated
Examples
- His crackbrained scheme to get rich quick failed miserably.
- She dismissed the proposal as another crackbrained idea.
- The crackbrained inventor claimed he could build a perpetual motion machine.
- Don’t listen to his crackbrained theories about aliens.
- The committee rejected the crackbrained plan to relocate the entire town.
- Her crackbrained notion of swimming across the lake in winter worried everyone.