sloop

noun3

1. •
   A single-masted sailboat with only one headsail.

   • Mr. Cooke had had a sloop yacht built at Far Harbor, the completion of which had been delayed, and which was but just delivered. — 1897
2. •
   A sailing warship, smaller than a frigate, with its guns all on one deck.
3. •
   A sloop-of-war, smaller than a frigate, larger than a corvette.