This from Wikipedia:
"The railroad historian, David L. Joslyn (a retired Southern Pacific Railroad draftsman), has connected caboose to kabhuis, a Middle Dutch word referring to the compartment on a sailing ship's main deck in which meals were prepared. Kabhuis is believed to have entered the Dutch language circa 1747 as a derivation of the obsolete Low German word kabhuse, which also described a cabin erected on a ship's main deck. However, further research indicates that this relationship was more indirect than that described by Joslyn.

Eighteenth century French naval records make reference to a cambose or camboose, which term described the food preparation cabin on a ship's main deck, as well as the range within. The latter sense apparently entered American naval terminology around time of the construction of the USS Constitution, whose wood-burning food preparation stove is officially referred to as the camboose.[3] These nautical usages are now obsolete: camboose and kabhuis became the galley when meal preparation was moved below deck, camboose the stove became the galley range, and kabuis the cookshack morphed into kombuis, which means kitchen in Afrikaans.

It is likely that camboose was borrowed by American sailors who had come into contact with their French counterparts during the American Revolution (recall that France was an ally and provided crucial naval support during the conflict). A New English Dictionary citation from the 1940s indicates that camboose entered English language literature in a New York Chronicle article from 1805 describing a New England shipwreck, in which it was reported that "...[survivor] William Duncan drifted aboard the canboose (sic)."[2] From this it could be concluded that camboose was part of American English by the time the first railroads were constructed. As the first cabooses were wooden shanties erected on flatcars (as early as the 1830s[4]) they would have resembled the cookshack on the (relatively flat) deck of a ship, explaining the adoption and subsequent corruption of the nautical term."