This word, shallop is courtesy of "Calidore. A Fragment" by John Keats.
And now he turns a jutting point of land, Whence may be seen the castle gloomy, and grand: Nor will a bee buzz round two swelling peaches, Before the point of his light shallop reaches Those marble steps that through the water dip: Now over them he goes with hasty trip, And scarcely stays to ope the folding doors: Anon he leaps along the oaken floors Of halls and corridors.
According to Wiktionary, shallop is an archaic word for one of two things: either "A type of large boat; a sloop" or "A small boat, a dinghy." Isn't it spectacular when a word can mean two opposing things? In this case, it's clear what the word meant from context: Calidore had previously been said to be traveling in a "little boat." Fortunate indeed that there was context available--I'm fairly sure I've never seen the word before.
According to COCA, shallop occurs about once in 32 million words in modern American English.