crack-brained in a sentence

Definition

Crack-brained: characterized by foolish or absurd ideas; wildly impractical or nonsensical.

His crack-brained scheme to build a rocket in his backyard left everyone bewildered.
The team's crack-brained strategy led them to make decisions that seemed wildly impractical.
She often dismissed his crack-brained ideas as nothing more than whimsical fantasies.
Despite his crack-brained theories about time travel, his passion for science was infectious.
The novel featured a crack-brained inventor whose eccentricities made him an endearing character.