side effect
noun
: a secondary and usually adverse effect (as of a drug)
toxic side effects
called also side reaction
Examples of side effect in a Sentence
Nausea and diarrhea are the side effects of the drug.
the harmful side effects of using chemicals to kill insects
The merger created positive side effects for both companies.
Recent Examples on the Web
Her only side effect was fatigue.
—
Kerry Breen, CBS News, 7 Mar. 2026
This side effect, which happens in the liver, may lead to unwanted weight gain.
—Kirsten Nunez, Martha Stewart, 7 Mar. 2026
Leucovorin is a form of folic acid used to reduce side effects from some chemotherapy drugs and treat folate deficiency.
—Liz Neporent, ABC News, 6 Mar. 2026
As Ozempic use becomes more and more prevalent in people’s lives, so does dealing with all of its side effects.
—Audrey Noble, Vogue, 6 Mar. 2026
See All Example Sentences for side effect
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Kerry Breen, CBS News, 7 Mar. 2026
This side effect, which happens in the liver, may lead to unwanted weight gain.
—Kirsten Nunez, Martha Stewart, 7 Mar. 2026
Leucovorin is a form of folic acid used to reduce side effects from some chemotherapy drugs and treat folate deficiency.
—Liz Neporent, ABC News, 6 Mar. 2026
As Ozempic use becomes more and more prevalent in people’s lives, so does dealing with all of its side effects.
—Audrey Noble, Vogue, 6 Mar. 2026
See All Example Sentences for side effect
Cite this Entry
“Side effect.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/side%20effect. Accessed 9 Mar. 2026.
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