WordWeb Online

1. [slang] Informal or slang term meaning insane, strange, eccentric or stupid
   "I think he's going dippy";
   - balmy [archaic, slang], barmy [slang], bats [slang], batty [slang], bonkers [slang], buggy [N. Amer, slang], cracked [slang], crackers [slang], daft [Brit, slang], dotty [slang], fruity [slang], haywire [slang], kooky [slang], kookie [slang], loco [slang], loony [slang], loopy [slang], nuts [slang], nutty [slang], round the bend [slang], around the bend [slang], wacky [slang], whacky [slang], doolally [Brit, slang], daffy [slang], nutsy [N. Amer, slang], potty [Brit, slang], daft as a brush [Brit, slang], round the twist [Brit, slang], wacko [slang], dumbass [N. Amer, slang], bughouse [N. Amer, slang], cuckoo [slang], mental [slang], barking mad [Brit, slang], barking [Brit, slang]
    
2. Guided by whim and fancy
   "dippy young girls";
   - flighty, flyaway, head-in-the-clouds, scatterbrained

Derived forms: dippier, dippiest

See also: ditsy [N. Amer, informal], ditzy [N. Amer, informal], frivolous, insane

Encyclopedia: Dippy