Vulcan

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The god of fire and metalworking.

from The Century Dictionary.

• noun In Roman mythology, the god of fire and the working of metals, and the patron of all handicraftsmen.
• noun A hypothetical planet between the sun and the planet Mercury.
• noun A volcano.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Rom. Myth.) The god of fire, who presided over the working of metals; -- answering to the Greek Hephæstus.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• proper noun Roman mythology The god of volcanoes and fire, especially the forge, also the patron of all craftsmen, principally blacksmiths.
• proper noun astronomy, historical A hypothetical planet proposed to exist in an orbit between Mercury and the Sun in a 19th-century hypothesis.
• proper noun A town in southern Alberta, Canada.
• proper noun A fictional inhabited planet.
• noun slang, pejorative A person who seems to lack emotion or is overly analytical and boring.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun (Roman mythology) god of fire and metal working; counterpart of Greek Hephaestus