1
a
: a pungent yellow condiment consisting of the pulverized seeds of various mustard plants (such as Sinapis alba, Brassica juncea, and B. nigra) either dry or made into a paste or sauce (as by mixing with water or vinegar) and sometimes adulterated with other substances (such as turmeric) or mixed with spices
b
: the seed of a mustard plant used as a spice and in medicine as a stimulant and diuretic, an emetic, or a counterirritant
c
slang : zest
2
: any of several herbs (genera Brassica and Sinapis of the family Brassicaceae synonym Cruciferae, the mustard family) with lobed leaves, yellow flowers, and linear beaked pods
3
: a dark to moderate yellow
see also:

Illustration of mustard

Illustration of mustard
  • mustard 2

Examples of mustard in a Sentence

Would you like some mustard on your hot dog?
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.
Sow your arugula seeds in a spot with plenty of sun and well-draining, loamy soil, avoiding areas where other cruciferous or mustard-related veggies have been in the past year. — The Spruce, 24 Sep. 2026 Combine the cashews, mustard (if using), garlic, nutritional yeast, soy milk, lemon juice, and salt in a high-speed blender and blend until smooth. — ABC News, 24 Sep. 2026 The sitdown and drive-thru space will offer its signature Wicked Wings with Lotta Zing spice and Golden Tenders with a choice of sauce (Lotta Zing sauce, BBQ, honey mustard or ranch). — Kansas City Star, 23 Sep. 2026 Stir together melted butter, mustard, onion powder, and garlic powder in a small bowl. — Elizabeth Nelson, Southern Living, 18 Sep. 2026 See All Example Sentences for mustard

Word History

Etymology

Middle English, from Anglo-French mustarde, from must must, from Latin mustum

First Known Use

13th century, in the meaning defined at sense 1a

Time Traveler
The first known use of mustard was in the 13th century

Browse Nearby Words

Cite this Entry

“Mustard.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mustard. Accessed 27 Sep. 2026.

Kids Definition

1
: any of several yellow-flowered herbs related to the turnips and cabbages
2
a
: a yellow sharp-tasting condiment consisting of the crushed seeds of various mustard plants either dry or made into a paste or sauce
b
: the seeds of a mustard plant

Medical Definition

1
: a pungent yellow condiment consisting of the pulverized seeds of the black mustard or sometimes the white mustard either dry or made into a paste and serving as a stimulant and diuretic or in large doses as an emetic and as a counterirritant when applied to the skin as a poultice
2
: any of several herbs (genus Brassica of the family Brassicaceae synonym Cruciferae, the mustard family) with lobed leaves, yellow flowers, and linear beaked pods see black mustard sense 1, white mustard
3

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