1. Having sharp differences between black and white

See also: contrast

Antonym: flat

• optimisation
• optimise
• optimism
• optimist
• optimistic
• optimistically
• optimization
• optimize
• optimum
• option
• optional
• optionally
• optometrist
• optometry
• opulence
• opulent
• opulently
• Opuntia
• Opuntia cholla
• Opuntia lindheimeri
• Opuntia tuna
• Opuntiales
• opus
• opuscule
• opusculum