• (a.) Of or pertaining to Vulcan; made by Vulcan; Vulcanian. • (a.) Of or pertaining to volcanoes; specifically, relating to the geological theory of the Vulcanists, or Plutonists.
Vul·can'ic adjective 1. Of or pertaining to Vulcan; made by Vulcan; Vulcanian. 2. Of or pertaining to volcanoes; specifically, relating to the geological theory of the Vulcanists, or Plutonists. 
Vulcanic is British slang for sexually frustrated.