plural hashtags
: a word or phrase preceded by the symbol # that classifies or categorizes the accompanying text (such as a tweet)
Using the hashtag #shedeservedthepurse, people are recording themselves hiding money and gift cards in baby staples like diaper boxes and formula containers for moms to find and use to treat themselves.—Meghan Overdeep
You know a thing is really a thing these days when it has its own hashtag. And there it was last week, trending on Twitter alongside #cincodemayo and #happymothersday: #umpshow, which sprang up in the wake of some shockingly bad umpiring over the first six weeks of the major league season.—Joe Sheehan
It's also true that a popular hashtag can benefit important and worthy subjects, such as the recently kidnapped Nigerian schoolgirls.—Mark Leibovich
also : the symbol # as used in a hashtag

Did you know?

Hashtags are an everyday part of Internet culture, thanks to social media. Originally designed for categorizing posts (i.e., tagging them) on Twitter, hashtags now commonly also supplement or comment on whatever text or image they accompany. The “hash” in hashtag is short for hash mark, a term for what we also call a pound sign or, if you want to apply the word-nerdiest designation, an octothorpe. Hash in this case is probably an alteration of hatch, a term for the lines artists sometimes use to add shading to a drawing. #WordNerdery

Examples of hashtag in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
That same year, Cisternas and Espinoza started throwing parties in Santiago under the hashtag #NeoPerreo. — Los Angeles Times, 22 Oct. 2026 The post included the hashtag #PisteandoConLaRegidaVol4, which may reference the upcoming live project, though Fuerza Regida has not publicly confirmed that as its title. — Isabela Raygoza, Billboard, 18 Oct. 2026 Which, as Vogue Business reported, has over 9 million videos under the #WitchTok hashtag. — Nicole Kliest, Vogue, 16 Oct. 2026 Some popular hashtags on TikTok include #OzempicFashion, #GLP1WeightLoss, #MidsizeRental and #ThredUpHaul. — Arthur Zaczkiewicz, Footwear News, 9 Oct. 2026 See All Example Sentences for hashtag

Word History

First Known Use

2007, in the meaning defined above

Time Traveler
The first known use of hashtag was in 2007

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Cite this Entry

“Hashtag.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hashtag. Accessed 25 Oct. 2026.

Kids Definition

hashtag

noun
hash·​tag
ˈhash-ˌtag
: a word or phrase preceded by the symbol # that classifies or categorizes the accompanying text (as a tweet)
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