1. Causing fear or dread or terror
   - awful, dire, direful, dread, dreaded, dreadful, fearful, frightening, horrendous, horrific, terrible

See also: alarming, fearsomely

• 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
• Oliver Ellsworth
• Oliver Goldsmith
• Oliver Hardy
• Oliver Hazard Perry
• Oliver Heaviside
• Oliver Stone
• Oliver Wendell Holmes