hashtag

[hash-tag]Digital Technology

noun

(on social media websites) a word or phrase preceded by a hash mark (#), used within a message to identify a keyword or topic of interest and facilitate a search for it: The hashtag #sandiegofire was used to help coordinate an emergency response to the fire.
a hash mark used in this way.

verb (used with or without object), hash·tagged, hash·tag·ging.

to add a hashtag to (a word, topic, or message): Someone on Twitter just hashtagged the film festival.

Origin of hashtag

2005–10; hash (mark) + tag¹ (in the sense “a label or keyword”)

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for hashtag

Contemporary Examples of hashtag

Michelle Obama tweeting a hashtag is somehow cause for outrage.
Political Memes That Absolutely Must Die in 2015
Asawin Suebsaeng
January 1, 2015
Who even needs a court of law, let alone victim testimony, now that we have the hashtag?
Shut Up, Lady Gaga’s Rape Isn’t About You
Amy Zimmerman
December 4, 2014
The hashtag has been used to label general rants about people getting naked for attention.
#FixTheInternet: The Hashtag That Beat Back Kim Kardashian’s Butt
Emily Shire
November 14, 2014
Go home and use that hashtag to let people know about the story.
The Dishonor of Honor Killings
Sara Stewart
October 20, 2014
And briefly, it seemed like a hashtag triumph—pretty much everyone, everywhere, was outraged.
When Activism Is Worse Than Apathy
Nancy Kaffer
October 6, 2014

British Dictionary definitions for hashtag

hashtag

noun

(on the Twitter website) a word or phrase preceded by a hash mark, used to denote the topic of a post

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012