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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
Also, given the medicine isn’t designed to help with fertility and pregnancy, there could be harmful side effects.
—Dominique Fluker, Essence, 25 Oct. 2024
Based on research to date, creatine monohydrate is safe and well-tolerated, with minimal side effects in healthy people.
—Jennifer Lefton, Ms, Rd/n, Cnsc, Fand, Verywell Health, 24 Oct. 2024
What are the side effects of the antidepressant drug Duloxetine?
—Chris Sims, The Courier-Journal, 24 Oct. 2024
Like with any immunization, though, there can be side effects.
—Beth Ann Mayer, Parents, 24 Oct. 2024
See all Example Sentences for side effect
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Word History
First Known Use
1814, in the meaning defined above
Dictionary Entries Near side effect
Cite this Entry
“Side effect.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/side%20effect. Accessed 7 Nov. 2024.
Kids Definition
side effect
noun
: an often harmful and unwanted effect (as of a drug) that occurs along with the basic desired effect
the environmental side effects of using chemicals to kill pests
Medical Definition
side effect
noun
: a secondary and usually adverse effect (as of a drug)
toxic side effects
a side effect of drowsiness caused by antihistamines
called also side reaction
More from Merriam-Webster on side effect
Thesaurus: All synonyms and antonyms for side effect
Nglish: Translation of side effect for Spanish Speakers
Britannica English: Translation of side effect for Arabic Speakers
Britannica.com: Encyclopedia article about side effect
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