a boat equipped with firefighting equipment, used in harbors, etc.
fireboat in American English
(ˈfaiᵊrˌbout)
noun
a powered vessel equipped to fight fires on boats, docks, shores, etc.
Word origin
[1875–80; fire + boat]This word is first recorded in the period 1875–80. Other words that entered Englishat around the same time include: hat trick, knockabout, massage, slime mold, weekender
2019, 'Without Warning, Molasses Surged Over Boston 100 Years Ago This Week', Smithsonianhttps://www.smithsonianmag.com/history/without-warning-molasses-january-surged-over-boston-180971251/