Topsail
/ˈtɑːpseɪl,ˈtɑːpsl/
Definition 1 of 1
Pro Tip 1/3Nautical Term
Used specifically in sailing contexts to refer to a part of a ship's rigging. 
During the voyage, we had to repair the topsail after a storm.
Pro Tip 2/3Historical Usage
'Topsail' is a traditional term more common in historical or maritime texts. 
The old galleon's topsail unfurled as it set out to sea.
Pro Tip 3/3Visual Cue
A topsail is typically above the main sail when visualizing a ship. 
From the shore, you could see the ship's topsail against the horizon.