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 The person passing on the infection need not have symptoms to transmit the infection, although the presence of a cold sore dramatically increases the likelihood of infection. Dr. Keith Roach, oregonlive, 16 Sep. 2021 The object is to avoid kissing the one with the cold sore. Washington Post, 5 Aug. 2021 One 2017 study looked at 23 common infections including chickenpox, shingles and cold sores and found genes that seemed to be associated with many of them. oregonlive, 20 Apr. 2020 Herpes type 1 or oral herpes is a virus that causes painful cold sores on your mouth and lips. Yerin Kim, Seventeen, 16 Jan. 2020 Researchers affilated with the organization estimated that 3.7 billion people under the age of 50 are infected with HSV-1, the type of herpes most people associate with cold sores on the mouth. Kristine Thomason,, 29 Oct. 2019 Cold and flu virus, cold sores, those viruses they're not usually not transferred through food. NBC News, 28 Nov. 2019 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, 19 Sep. 2019 Neither Angus or myself have ever had a cold sore in our lives. Michelle Gant, Fox News, 19 July 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.

See More

First Known Use of cold sore

1870, in the meaning defined above

Learn More About cold sore

Time Traveler for cold sore

Time Traveler

The first known use of cold sore was in 1870

See more words from the same year

Dictionary Entries Near cold sore

cold soldering

cold sore

cold spell

See More Nearby Entries 

Statistics for cold sore

Cite this Entry

“Cold sore.” Dictionary, Merriam-Webster, Accessed 25 Jan. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

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

More from Merriam-Webster on cold sore Encyclopedia article about cold sore


Test Your Vocabulary

Difficult Spelling Words Quiz

  • alphabet pasta spelling help
  • Which is the correct spelling?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!