sulfurous

adjective

sul·​fu·​rous ˈsəl-fə-rəs 

-fyə-,

also (especially for sense 1a)

ˌsəl-ˈfyu̇r-əs 

variants or chiefly British sulphurous

1

a

: of, relating to, or containing sulfur especially with a lower valence than sulfuric compounds

sulfurous esters

b

: resembling or emanating from sulfur and especially burning sulfur

2

a

: of, relating to, or dealing with the fire of hell : infernal

b

: scathing, virulent

sulfurous denunciations

c

: profane, blasphemous

sulfurous language

sulfurously adverb

sulfurousness noun

Is it sulfur or sulphur?: Usage Guide

The spelling sulfur predominates in U.S. technical usage, while both sulfur and sulphur are common in general usage. British usage tends to favor sulphur for all applications. The same pattern is seen in most of the words derived from sulfur.

Examples of sulfurous in a Sentence

Recent Examples on the Web

The team used soda pulping as one part of the process—boiling the raw material in lye as opposed to the sulfurous byproducts found in traditional (kraft) pulping—to make manufacturing more sustainable. —Alexandra Harrell, Sourcing Journal, 3 Sep. 2019

The large red ring is sulfurous fallout from the plume of the Pele volcano. —Robin Andrews, Wired News, 15 June 2025

By 1990, bootleg versions of the book had washed up for sale in the pages of far-right magazines, peddled alongside sulfurous predictions of American concentration camps and a helpful who’s who of global elitists. —Dan Piepenbring, Harper's Magazine, 19 Feb. 2025

Concerts have taken place in a pineapple greenhouse, a tea factory, and even a geothermal bath, where 800 attendees soaked in sulfurous yellow water while listening to the ethereal electro-pop of Basque singer-songwriter Verde Prato. —Philip Sherburne, Condé Nast Traveler, 17 Aug. 2024

Word History

First Known Use

15th century, in the meaning defined at sense 1a

Phrases Containing sulfurous

• sulfurous acid

Rhymes for sulfurous

• sulphurous

Kids Definition

sulfurous

adjective

sul·​fu·​rous

variants also sulphurous

ˈsəl-f(y)ə-rəs 

also for sense 1

ˌsəl-ˈfyu̇r-əs 

1

: of, relating to, or containing sulfur

2

a

: of, relating to, or dealing with the fire of hell : infernal

b

: fiery sense 3a, inflamed

a sulfurous sermon

c

: profane sense 2, blasphemous

sulfurous language

Medical Definition

sulfurous

adjective

sul·​fu·​rous

variants or chiefly British sulphurous

ˈsəl-f(y)ə-rəs, also especially for 1 ˌsəl-ˈfyu̇r-əs

1

: of, relating to, or containing sulfur especially with a lower valence than sulfuric compounds

sulfurous esters

2

: resembling or emanating from sulfur and especially burning sulfur