Definition of "sloop"

I stayed in this island for a few days; I believe it could not be above a fortnight; when I and some few more slaves, that were not saleable amongst the rest, from very much fretting, were shipped off in a sloop for North America.

1789, Olaudah Equiano (Gustavus Vassa), The Interesting Narrative of the Life of Olaudah Equiano

And where but from Nantucket, too, did that first adventurous little sloop put forth, partly laden with imported cobblestones—so goes the story—to throw at the whales, in order to discover when they were nigh enough to risk a harpoon from the bowsprit?

1851 November 14, Herman Melville, chapter 2, in Moby-Dick; or, The Whale, 1st American edition, New York, N.Y.: Harper & Brothers; London: Richard Bentley, page 8

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 December (indicated as 1898), Winston Churchill, chapter X, in The Celebrity: An Episode, New York, N.Y.: The Macmillan Company; London: Macmillan & Co., Ltd.