whacky

Adjective

• informal or slang terms for mentally irregular
  • it used to drive my husband balmy
    

• ludicrous, foolish
  • gave me a cockamamie reason for not going
    
  • wore a goofy hat
    
  • a silly idea
    
  • some wacky plan for selling more books
    

Related words

• Synonyms: 
  balmy , barmy , bats , batty , bonkers , buggy , cracked , crackers , daft , dotty , fruity , haywire , kooky , kookie , loco , loony , loopy , cockamamie , cockamamy , goofy , sappy , silly , wacky , zany