Sulphureous is an adjective that denotes something that has a pungent smell or taste like that of sulphur. It is often used to describe volcanic gases, rotten eggs, or heavy industrial pollution. Synonyms for sulphureous include sulfuric, sulfurous, stinking, putrid, foul-smelling, and malodorous. Other related words include odiferous, fetid, noxious, acrid, and musty. These synonyms are useful when describing odors or flavors that have a sharp, unpleasant, or rotten quality. As a result, they can be used interchangeably with sulphureous in many contexts, including discussions about geology, chemistry, and pollution control.