sul·fur (US) or chiefly Brit sul·phur 
/ˈsʌlfɚ/ noun
/ˈsʌlfɚ/ noun [noncount] chemistry : a yellow chemical element that has a strong, unpleasant odor when it is burned and that is used in making paper, gunpowder, medicine, etc.
usage In U.S. English, the spelling sulfur is chiefly used in technical writing, while both sulfur and sulphur are common in general writing.
