: any of various vigorous weedy plants especially of the amaranth family
Examples of pigweed in a Sentence
Recent Examples on the Web
When pigweed is young, hoeing is often all that is needed to kill it, but due to the deep taproot, established older plants are difficult to remove.
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Andy Wilcox, Better Homes & Gardens, 27 Aug. 2025
Then, once applications of Roundup annihilated all the weeds in a field except the resistant Palmer amaranth, the pigweed could spread without competition.
—New York Times, 11 Aug. 2021
Peppers and Pigweed Leafminers preferred both pigweed (also called amaranthus) and ragweed to pepper plants in a study at the Coastal Plains Experiment Station in Tifton, Georgia.
—The Editors, Good Housekeeping, 24 Apr. 2020
Some farmers who plant dicamba-tolerant soybeans and cotton say dicamba's use during the height of the growing season is their only defense against pigweed, an invasive plant that has mutated and has become resistant to glyphosate herbicides.
—Stephen Steed, Arkansas Online, 20 Dec. 2019
The list of allergens includes – but is not limited to — latex, gold, pollen (ragweed, cockleweed and pigweed are especially bad), penicillin, insect venom, peanuts, papayas, jellyfish stings, perfume, eggs, the feces of house mites, pecans, salmon, beef and nickel.
—Carl Zimmer, Discover Magazine, 20 July 2015
The Palmer amaranth, a type of pigweed that was originally native to the deserts of Mexico and the southwestern U.S., can out-compete most commercial crops, is highly resistant to common herbicides and can be toxic to livestock.
—Gregory B. Hladky, courant.com, 12 Aug. 2014
Terrance Hurley Department of Applied Economics University of Minnesota
Adler’s characterization of ragweed and pigweed (Palmer amaranth) as monsters is plain silly.
—The Editors, Scientific American, 1 Sep. 2011
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Andy Wilcox, Better Homes & Gardens, 27 Aug. 2025
Then, once applications of Roundup annihilated all the weeds in a field except the resistant Palmer amaranth, the pigweed could spread without competition.
—New York Times, 11 Aug. 2021
Peppers and Pigweed Leafminers preferred both pigweed (also called amaranthus) and ragweed to pepper plants in a study at the Coastal Plains Experiment Station in Tifton, Georgia.
—The Editors, Good Housekeeping, 24 Apr. 2020
Some farmers who plant dicamba-tolerant soybeans and cotton say dicamba's use during the height of the growing season is their only defense against pigweed, an invasive plant that has mutated and has become resistant to glyphosate herbicides.
—Stephen Steed, Arkansas Online, 20 Dec. 2019
The list of allergens includes – but is not limited to — latex, gold, pollen (ragweed, cockleweed and pigweed are especially bad), penicillin, insect venom, peanuts, papayas, jellyfish stings, perfume, eggs, the feces of house mites, pecans, salmon, beef and nickel.
—Carl Zimmer, Discover Magazine, 20 July 2015
The Palmer amaranth, a type of pigweed that was originally native to the deserts of Mexico and the southwestern U.S., can out-compete most commercial crops, is highly resistant to common herbicides and can be toxic to livestock.
—Gregory B. Hladky, courant.com, 12 Aug. 2014
Terrance Hurley Department of Applied Economics University of Minnesota
Adler’s characterization of ragweed and pigweed (Palmer amaranth) as monsters is plain silly.
—The Editors, Scientific American, 1 Sep. 2011
Cite this Entry
“Pigweed.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/pigweed. Accessed 9 Sep. 2025.
Copy CitationKids Definition
pigweed
noun
pig·weed
-ˌwēd 
: any of various weedy plants especially of the two families to which the goosefoots and amaranths belong
Medical Definition
pigweed
noun
pig·weed
ˈpig-ˌwēd
: any of several plants of the genus Amaranthus (as A. retroflexus and A. hybridus) with pollen that acts as a hay fever allergen
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