cold sore


Definition of cold sore

: a group of fluid-filled blisters appearing about or within the mouth that are caused by a herpes simplex virus and upon rupturing form crusts

called also fever blister

— compare canker sore

Examples of cold sore in a Sentence

Recent Examples on the Web Numbing medication caused her reaction In his patient’s case, her reaction was caused by benzocaine, an active ingredient found in over-the-counter toothache and cold sore medicine. Wire Service, The Mercury News, "A woman used a numbing agent to treat a toothache. The next day her blood turned blue," 19 Sep. 2019 Neither Angus or myself have ever had a cold sore in our lives. Michelle Gant, Fox News, "Parents whose newborn babies died from herpes warn about deadly virus," 19 July 2018 There’s some indication that an immune reaction—perhaps from something as seemingly benign as the microbes that cause cold sores or gum disease—could be a spark that launches a series of events that ultimately lead to an Alzheimer’s diagnosis. Karen Weintraub, Scientific American, "Alzheimer’s Meeting: Lifestyle Factors Are the Best—and Only—Bet Now for Reducing Dementia Risk," 18 July 2019 For instance, overexposure to sunlight can bring about immune system suppression, which is why some people with herpes develop cold sores after spending time in the sun. Nina Bahadur, SELF, "Why Does Spending Time in the Sun Make You So Tired?," 8 Sep. 2018 But despite being a great source of vitamins and minerals, the plans—which claim to flush the body of toxins, curing everything from headaches, nausea, and fatigue to cold sores, insomnia, and yeast infections—are controversial. Courtney Rubin, Marie Claire, "Cleansing's Dirty Secret," 26 Apr. 2013 What about using tea tree oil for things like cold sores and warts? Krissy Brady, SELF, "What Tea Tree Oil Can and Can’t Do for Your Skin," 4 Oct. 2018 That's another symptom, but the fear spreads faster than a cold sore from Bill Clinton. Fox News, "Gutfeld: Be nicer. It will drive your enemies nuts," 5 Aug. 2018 Benzocaine is also used in popular over-the-counter products for toothaches and cold sores in adults, including Orajel and Anbesol and generic drugstore brands. Matthew Perrone,, "FDA warns teething medicines unsafe, wants them off shelves," 24 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cold sore.' 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 cold sore

1870, in the meaning defined above

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Time Traveler for cold sore

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The first known use of cold sore was in 1870

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Statistics for cold sore

Last Updated

11 Nov 2019

Cite this Entry

“Cold sore.” The Dictionary, Merriam-Webster Inc., Accessed 9 December 2019.

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More Definitions for cold sore

cold sore


English Language Learners Definition of cold sore

: a small sore area around or inside the mouth that is caused by a virus

cold sore


Medical Definition of cold sore

: a vesicular lesion that typically occurs in or around the mouth, that initially causes pain, burning, or itching before bursting and crusting over, and that is caused by a herpes simplex virus which remains dormant in the body and may be reactivated by a variety of factors (as stress, fever, or sunburn)

called also fever blister

— compare canker sore

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More from Merriam-Webster on cold sore

Rhyming Dictionary: Words that rhyme with cold sore

Spanish Central: Translation of cold sore Encyclopedia article about cold sore

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