WordWeb Online

1. Foolish; totally unsound
   "a screwball proposal without a prayer of working";
   - crazy, half-baked, softheaded, nutty, crackpot, wiggy [US]

1. A whimsically eccentric person
   - crackpot, crank, nut, nut case, fruitcake
    
2. A pitch with reverse spin that curves toward the side of the plate from which it was thrown

Derived forms: screwballs

See also: impractical

Type of: dag [Austral, NZ], delivery, eccentric, eccentric person, flake [N. Amer], geek, oddball, pitch

Encyclopedia: Screwball