The word volcano is named after a god's workshop.
The English word comes from Italian vulcano, "burning mountain," which comes from Latin Vulcanus, Vulcan, the Roman god of fire and metalworking. In Latin the name could also stand for fire or flames in general. Etymonline dates volcano in English to the 1610s.
The Romans gave the god a physical address. According to Wikipedia's article on the island, they believed the small island of Vulcano, in the Aeolian group off Sicily, was Vulcan's chimney. They imagined the island had grown from the cinders and ash he cleared from his forge, and they read the earthquakes before its ash explosions as the god making weapons for Mars. Etymonline, which does not mention the island, says the Romans applied the name to Mount Etna because they believed it was Vulcan's forge.
The idea was borrowed. Wikipedia notes that the Greeks had already made Vulcano a foundry of Hephaestus, their god of blacksmiths, and named two other foundries at Etna and Olympus. The Greeks called the island Thermessa, which that page glosses as "source of heat."
Wikipedia says the English word and its equivalents in several European languages derive from the island's name. Dictionaries such as Etymonline simply trace it to the god's name via Italian. Either way, the Roman belief behind it is myth, not recorded history.
English had touched the word earlier in other forms. Etymonline lists vulcane in the late 14th century, borrowed from French, and volcan in the 1570s, before the modern spelling settled.
The god kept producing vocabulary. Vulcan is recorded in English from the 1510s, and in 1860 the name was given to a hypothetical planet between Mercury and the Sun. Etymonline says the god's own name is possibly of Etruscan origin, which would put the root of "volcano" outside Latin altogether. Later scientists reached back to the island again: the "Vulcanian" style of eruption is based on Giuseppe Mercalli's description of the 1888 to 1890 eruption on Vulcano itself.