I. sul ‧ fur /ˈsʌlfə $ -ər/ BrE AmE noun [uncountable]
the American spelling of ↑ sulphur
II. sul ‧ phur BrE AmE British English , sulfur American English /ˈsʌlfə $ -fər/ noun [uncountable]
a common light yellow chemical substance that burns with a very strong unpleasant smell, and is used in drugs, explosives, and industry. It is a chemical ↑ element : symbol S