Having to do with sulphur, containing sulphur, or made with sulphur. Sulphur is the yellow chemical element that smells like rotten eggs when it burns. So we talk about sulphurous gas coming out of a volcano, sulphurous smoke from burning coal, or a sulphurous smell near a hot spring. Two things to notice about how people really use it. First, most of the time the word is doing a nose job, not a chemistry job — when someone writes "a sulphurous smell", they usually just mean that bad egg smell, and they may not know or care whether real sulphur is there. Second, writers stretch it to describe anger. A "sulphurous look" or "sulphurous language" means someone is burning with rage, or swearing badly. That comes from the old picture of hell full of burning sulphur. This stretched use is literary; you will meet it in novels, not in conversation. About the spelling: British writing uses sulphur / sulphurous, American writing uses sulfur / sulfurous. They are the same word. Scientists everywhere now write sulfur officially, so in a chemistry class you will see the f. The word is formal and not common in speech — people say "it smells like sulphur" or in Taiwan simply "it smells like rotten eggs" instead.

含硫的、硫磺（味）的。台灣講溫泉、火山那股味道時，日常多半直接說「硫磺味」，形容詞的部分中文常常不另外翻。書面上寫「硫的」「含硫的」。注意台灣的化學課本用「硫」這個字，「硫磺」偏日常、偏那個黃色塊狀的東西。文學裡罵人氣得像地獄之火那種用法，中文可以說「像要噴火似的」，不會照字面翻成硫。