1. Of black tinged with grey
   - gray-black [US], greyish-black [Brit, Cdn], grayish-black [US]

See also: achromatic, neutral

• optically
• optician
• optics
• optimal
• optimally
• optimisation
• optimise
• optimism
• optimist
• optimistic
• optimistically
• optimization
• optimize
• optimum
• option
• optional
• optionally
• optometrist
• optometry
• opulence
• opulent
• opulently
• Opuntia
• Opuntia cholla
• Opuntia lindheimeri