sulfur

noun

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
ˈsəl-fər-ē How to pronounce sulfur (audio)
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 sulfur in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The mix of lactic, malic and salicylic acids, sulfur, and niacinamide helps slough away dead skin cells, keep acne breakouts in check, and brighten up any dark spots or hyperpigmentation. — Audrey Noble, Vogue, 27 July 2026 Both are trisulfides, a class of molecules containing three sulfur atoms connected in sequence. — Angel Saunders, PEOPLE, 25 July 2026 Researchers think the moon is blanketed by porous layers of volcanic ash, sulfur frost and other eruptive debris that continually resurface Io, burying older terrain beneath fresh deposits. — Samantha Mathewson, Space.com, 24 July 2026 To solve this degradation problem, the research team focused on a specific sulfide solid electrolyte known as lithium phosphorus sulfur chloride (LPSCl). — Mrigakshi Dixit, Interesting Engineering, 17 July 2026 See All Example Sentences for sulfur

Word History

Etymology

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

Phrases Containing sulfur

Rhymes for sulfur

See All Rhymes for sulfur

Browse Nearby Words

sulfoxylic acid
sulfur
sulfurator
See all Nearby Words

Cite this Entry

“Sulfur.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/sulfur. Accessed 1 Aug. 2026.

Copy Citation

Kids Definition

sulfur

noun
sul·​fur
variants also sulphur
ˈsəl-fər How to pronounce sulfur (audio)
: 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 noun
sul·​fur
variants or chiefly British sulphur
ˈsəl-fər How to pronounce sulfur (audio)
: 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

sulfur

2 of 2 adjective
variants or chiefly British sulphur
: of, relating to, or resembling sulfur : containing or impregnated with sulfur

More from Merriam-Webster on sulfur

Nglish: Translation of sulfur for Spanish Speakers

Britannica.com: Encyclopedia article about sulfur

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of spindrift

See Definitions and Examples »

Popular in Grammar & Usage

See More

7 Pairs of Commonly Confused Words

Merriam-Webster’s Great Big List of Words You Love to Hate

Is it 'nerve-racking' or 'nerve-wracking'?

Why does English have so many silent letters?

Your vs. You're: How to Use Them Correctly
See More

Popular in Wordplay

See More

Dutch Treat and French Leave: Eight Place-Based Compounds

14 Phobias You Probably Haven't Heard Of

The Longest Long Words List

The Words of the Week - Jul. 31

Even More Bird Names that Sound Like Insults (and Sometimes Are)
See More

Popular

See More

7 Pairs of Commonly Confused Words

Dutch Treat and French Leave: Eight Place-Based Compounds

14 Phobias You Probably Haven't Heard Of
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
asap street sign
Figure Out These Acronyms ASAP You don't have to be a NASA engineer to get these...
See All