1. Someone regarded as eccentric or crazy and standing out from a group
   - kook [N. Amer], odd fellow, odd fish, queer bird, queer duck, odd man out

Type of: anomaly, unusual person

• oligotrophic
• oliguria
• Olimbos
• olio
• olivaceous
• olive
• olive branch
• olive drab
• olive family
• olive oil
• olive ridley
• olive tree
• olive-brown
• olive-colored
• olive-coloured
• olive-drab uniform
• olive-gray
• olive-green
• olive-grey
• olive-sized
• olive-tree agaric
• olivelike
• olivenite
• Oliver
• Oliver Cromwell