A vessel freighted with combustibles and explosives and set adrift, for the purpose of burning or blowing up an enemy's ships, a bridge, or other object.(noun)
The Century Dictionary (Public Domain)
Use "fire-ship" in a sentence
"The men dwelling on the lower reaches of the river heard the reports of big guns and saw a fire-ship of the Dutch amongst the islands of the estuary."
"But England (which never is allowed to do, without hooting and execration, what every other country does with loud applause) — England must rather burn off her right hand than send a fire-ship against the ships full of fire for her houses, her cottages, and churches."
"The “Chancellor” under bare poles, was driven, like a gigantic fire-ship with frightful velocity across the raging ocean; her very speed as it were, making common cause with the hurricane to fan the fire that was consuming her."