sulfurous

• sulphurous (mainly UK)

sulfur +‎ -ous

• (US) IPA^(key): /ˈsʌlfəɹəs/
• (UK) IPA^(key): /sʌlˈfjuɹəs/

sulfurous (comparative more sulfurous, superlative most sulfurous)

1. (American spelling) Containing sulfur.
   • 1817 December, Percy Bysshe Shelley, “The Revolt of Islam. […]”, in [Mary] Shelley, editor, The Poetical Works of Percy Bysshe Shelley. […], volume I, London: Edward Moxon […], published 1839, →OCLC, page 191:

     It must be so—I will arise and waken
     The multitude, and like a sulphurous hill,
     Which on a sudden from its snows had shaken
     The swoon of ages, it shall burst, and fill
     The world with cleansing fire; it must, it will—
     It may not be restrained!

2. (chemistry) Of, or relating to sulfur, especially in its lower oxidation state.

• sulfurous acid, sulphurous acid
• sulfurous chloride, sulphurous chloride

• sulfuric