1. A triangular fore-and-aft sail with its foot along the gaff and its luff on the topmast
   - fore-and-aft topsail

Type of: fore-and-aft sail

• 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