Definition of sulfur in English:

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Pronunciation: /ˈsəlfər/
(chiefly British also sulphur)


1The chemical element of atomic number 16, a yellow combustible nonmetal. (Symbol: S)
Example sentences
  • Potassium also reacts readily with all acids and with many nonmetals, such as sulfur, fluorine, chlorine, phosphorus, and nitrogen.
  • Other elements added to improve characteristics include nickel, molybdenum, copper, titanium, aluminum, silicon, niobium, nitrogen, sulfur, and selenium.
  • Along with carbon, they include elements such as hydrogen, oxygen, fluorine, chlorine, bromine, sulphur or nitrogen.
1.1The material of which hellfire and lightning were believed to consist.
Example sentences
  • The first Muslims saw that sulphur has qualities that do not exist in other stones, so they thought that it would be the fuel of Hell.
  • Neither the white-dwarf theory nor the the black-hole theory can explain the presence of sulfur (‘brimstone’) in the lake of fire, if it is to be taken literally.
1.2A pale greenish-yellow color: [as modifier]: the bird’s sulfur-yellow throat
More example sentences
  • Among aromatic double-flowered tulips we have the sulphur yellow ‘Monte Carlo’ and the golden ‘Hoangho’.
  • What they have in common are ball-like clusters of flowers of a bright sulfur yellow that fades to a softer orange-yellow as the seeds form.
  • Each stem carries up to 10 nodding sulphur coloured flared bell shaped flowers, growing from a base of deep green foliage that has attractive mottled markings.

Sulfur occurs uncombined in volcanic and sedimentary deposits, as well as being a constituent of many minerals and petroleum. It is normally a bright yellow crystalline solid, but several other allotropic forms can be made. Sulfur is an ingredient of gunpowder, and is used in making matches and as an antiseptic and fungicide.

2An American butterfly with predominantly yellow wings that may bear darker patches.
  • Colias, Phoebis, and other genera, family Pieridae.
Example sentences
  • Create a shallow puddle to attract swallowtails, blues, sulfurs and other butterflies that enjoy drinking at mud puddles.
  • Swallowtails, cabbage whites, skippers, and orange sulphurs follow scent trails to the tiny patches of flowers blooming furiously in the middle of the city.
  • The coyote approached a patch of wet earth where a dozen or more butterflies - monarchs and sulphurs - were getting a morning drink, and the insects scattered.


[with object]
Disinfect or fumigate with sulfur.
Example sentences
  • Recent experiments suggest that sulphuring an inverted barrel but not bunging up results in a much lower level of volatile acids since bunging up creates a humid environment, ideal for the growth of bacteria.
  • The wine was then handled like a white wine, cool fermented and sulphured once dry.
  • Fruits may be pretreated by sulfuring, salt solution, ascorbic acid solution, or steam blanching.


The standard US spelling is sulfur; sulphur is the traditional British spelling. However, the -f- spelling is now standard in scientific and technical writing in the UK, and is increasingly used in other contexts as well.



Pronunciation: /ˈsəlf(ə)rē/
Example sentences
  • Some pints even end up tasting of sulphury eggs, or goats' cheese.
  • The sky turned from light blue to sulphury yellow.
  • Cover with ‘cooking’ water (as tap water will leave a sulfury, metallic taste not consistent with traditional Jewish cooking).


Middle English: from Anglo-Norman French sulfre, from Latin sulfur, sulphur.

For editors and proofreaders

Syllabification: sul·fur

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