jon boat or jon·boat also john boat or john·boat 
(jŏnbōt′)
(jŏnbōt′)n.
A small flatbottom boat with square ends, used on shallow waterways.
[Probably alteration (influenced by the name Jon) of joe boat, variant spelling of jow boat, perhaps from Scots jow, to move with a rocking motion, from Middle English jollen, to stagger, knock, variant of chollen, to strike, perhaps from chavel, chaule, cheek; see JOWL1.]