side effect

noun

Definition of side effect

: 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.
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Recent Examples on the Web

Common side effects of benzoyl peroxide include flakiness, irritation, and, apparently... eyebrow bleaching? Nicola Dall'asen, Allure, "A Redditor Says Benzoyl Peroxide Cream Turned Her Brown Eyebrows Blonde," 23 Aug. 2019 Common side effects include dizziness, blurred vision, sleepiness and difficulty concentrating. CBS News, "FDA approves first generic copies of nerve pain drug Lyrica," 22 July 2019 The most common side effects of ORILISSA include: hot flashes or night sweats, headache, nausea, difficulty sleeping, absence of periods, anxiety, joint pain, depression, and mood changes. Vogue, "Rosalía Just Kickstarted Festival Season’s Unlikeliest Trend," 8 July 2019 The most common side effects of Vyleesi are nausea, headache and flushing. Michael Nedelman, CNN, "FDA approves new drug for women with low sexual desire disorder," 21 June 2019 The most common side effect in company studies was nausea. Washington Post, "New drug to boost women’s sex drive approved in US," 21 June 2019 The most common side effect in company studies was nausea. Matthew Perrone, BostonGlobe.com, "Waltham-based Amag’s sex-drive drug for women gets FDA approval," 21 June 2019 The most common side effects of ORILISSA include: hot flashes or night sweats, headache, nausea, difficulty sleeping, absence of periods, anxiety, joint pain, depression, and mood changes. Glamour, "The Biggest Swimwear Color Trends for Summer 2019," 25 May 2019 The most common side effects of ulipristal acetate are generally the same as levonorgestrel, including headache, stomach pain, wonky bleeding, and nausea. Natasha Lavender, SELF, "Here's How Emergency Contraception Actually Works," 1 Apr. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'side effect.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of side effect

1814, in the meaning defined above

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Statistics for side effect

Last Updated

12 Sep 2019

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Time Traveler for side effect

The first known use of side effect was in 1814

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More Definitions for side effect

side effect

noun

English Language Learners Definition of side effect

: an often harmful and unwanted effect of a drug or chemical that occurs along with the desired effect
: a result of an action that is not expected or intended

side effect

noun

Medical Definition of side effect

: 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

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More from Merriam-Webster on side effect

Rhyming Dictionary: Words that rhyme with side effect

Spanish Central: Translation of 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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