Synonyms for Nutty as fruitcake

Synonyms starting with letter O

• of unsound mind

  mentally strange, insane
• out to lunch

  mentally strange, insane
• off

  insane
• out-to-lunch
• out of all reason
• outrageous
• outlandish
• odd
• out of whack
• overboard
• orderless
• on a trip
• overwrought
• overstrung
• out of countenance
• on the warpath