/vol kay"noh/ , n. , pl. volcanoes, volcanos .
1. a vent in the earth's crust through which lava, steam, ashes, etc., are expelled, either continuously or at irregular intervals.
2. a mountain or hill, usually having a cuplike crater at the summit, formed around such a vent from the ash and lava expelled through it.
[ 1605-15; Volcanus, var. of Vulcanus VULCAN ]