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
Some appeals to stay on Zepbound have been approved and other people have been able to switch to Wegovy with only mild side effects, but the change has been disruptive for many patients and their doctors.
—
Deidre McPhillips, CNN Money, 5 Sep. 2025
The mixture is generally safe in small amounts, but excessive intake can cause side effects, such as tooth erosion and stomach upset.
—Lindsay Curtis, Verywell Health, 4 Sep. 2025
Other common side effects included nausea and headaches.
—Ken Alltucker, USA Today, 4 Sep. 2025
Serious side effects were rare.
—Dr. Christian S. Monsalve, ABC News, 4 Sep. 2025
See All Example Sentences for side effect
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Deidre McPhillips, CNN Money, 5 Sep. 2025
The mixture is generally safe in small amounts, but excessive intake can cause side effects, such as tooth erosion and stomach upset.
—Lindsay Curtis, Verywell Health, 4 Sep. 2025
Other common side effects included nausea and headaches.
—Ken Alltucker, USA Today, 4 Sep. 2025
Serious side effects were rare.
—Dr. Christian S. Monsalve, ABC News, 4 Sep. 2025
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 8 Sep. 2025.
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