sul·​fur ˈsəl-fər How to pronounce sulfur (audio)
variants or chiefly British sulphur
: a nonmetallic chemical element that is an essential element for all life, resembles oxygen in chemical properties, and is used especially in the form of sulfuric acid to extract phosphates from ores see Chemical Elements Table
sulfury adjective
or chiefly British sulphury
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.

Example Sentences

Recent Examples on the Web In 2010, California and the North American Emissions Control Area began limiting the amount of sulfur in this oil. WIRED, 21 Nov. 2022 At the neighboring Port of Long Beach, diesel particulate increased 42%, nitrogen oxides grew 35% and sulfur oxides rose 38%. Tony Briscoestaff Writer, Los Angeles Times, 17 Oct. 2022 The operations also pump out nitrogen oxides, sulfur oxides and polycyclic aromatic hydrocarbons, traces of which have been detected by scientists in soils and snowpack dozens of miles away. NBC News, 22 Nov. 2021 At peak levels and with certain mixtures, SAF can cut CO2 emissions by up to 80 percent and reduce particulate matter, sulfur oxides and nitrous oxides by large measures. J. George Gorant, Robb Report, 21 Sep. 2021 This achieved what the experiments with sulfur had failed to do: producing a contrail with tiny particles too small to see. David Hambling, Popular Mechanics, 15 Nov. 2022 Others want to release sulfur into the atmosphere akin to the way volcanoes work, which would cool things down. Joshua Hawkins, BGR, 10 Nov. 2022 Oxygen emission is blue, sulfur is orange, and hydrogen and nitrogen are green. Julia Musto, Fox News, 20 Oct. 2022 For example, several genes for processing selenium and for metabolizing sulfur have evolved rapidly in the western group, possibly to deal with the specific chemistry of hot springs there, Li suggests. Byelizabeth Pennisi,, 11 Oct. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sulfur.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


Middle English sulphur brimstone, from Latin sulpur, sulphur, sulfur

First Known Use

14th century, in the meaning defined above

Time Traveler
The first known use of sulfur was in the 14th century

Dictionary Entries Near sulfur

Cite this Entry

“Sulfur.” Dictionary, Merriam-Webster, Accessed 3 Dec. 2022.

Kids Definition



variants also sulphur
: a nonmetallic element that occurs either free or combined especially in sulfides and sulfates, is found in proteins, exists in several forms including yellow crystals, and is used especially in the chemical and paper industries, in strengthening rubber, and in medicine for treating skin diseases see element

Medical Definition

sulfur 1 of 2


variants or chiefly British sulphur
: a nonmetallic element that occurs either free or combined especially in sulfides and sulfates, is a constituent of proteins, exists in several allotropic forms including yellow orthorhombic crystals, resembles oxygen chemically but is less active and more acidic, and is used especially in the chemical and paper industries, in rubber vulcanization, and in medicine for treating skin diseases
symbol S
see Chemical Elements Table


2 of 2


variants or chiefly British sulphur
: of, relating to, or resembling sulfur : containing or impregnated with sulfur

More from Merriam-Webster on sulfur

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