Hashtag
noun /ˈhæʃ.tæɡ/ — A keyword phrase marked with # for social media categorization.
Definition
A word or phrase preceded by the # symbol, used on social media platforms to categorize content and make it discoverable by others searching for that tag. Hashtags can create movements, signal community, or simply organize content.
Beyond the definition
The hashtag turned a keyboard symbol into a social technology — a way of saying 'this belongs to that conversation' to a global audience. Its power lies in aggregation: alone, a single post; together, a movement.
Origin & history
The hash symbol (#) has been on keyboards since the 1960s. The hashtag as social media convention was proposed by Chris Messina on Twitter in 2007 and adopted in 2009.
Example sentences
Illustrative sentences for learning, not verified community posts or sourced quotations.
#MeToo turned a hashtag into a watershed — the categorization of experience creating the visibility of scale.
She hashtagged everything her brand touched, knowing the algorithm rewarded discoverability over spontaneity.
The most effective hashtags are specific enough to be meaningful and broad enough to aggregate reach.
How to use it
This entry uses a noun. Follow the examples for articles and singular or plural forms; not every noun takes “a” or “an.”
Choose “Hashtag” when the meaning fits your context: A word or phrase preceded by the # symbol, used on social media platforms to categorize content and make it discoverable by others searching for that tag. Hashtags can create movements, signal community, or simply organize content.
Synonyms
tag, keyword, category marker
Related words
Hashtag vs tag
A hashtag is a specific metadata tag prefixed by '#' for social media categorization. A 'tag' is a generic term for metadata or labels attached to items for organization.
Word in the Wild
See how this word appears in life, language and stories.
Illustrative sentences and imagined stories for learning — not verified sightings, interviews, or sourced quotations.
Fictional scene
Geometric Shapes on an Artifact
A tablet bears repeated geometric shapes, with a magnifying glass held over the desk surface.
The recurring symbols represent the categorical function of a hashtag. While these geometric shapes are ancient and mysterious, they serve the same role as a tag: grouping and identifying specific content so it can be discovered and analyzed within a larger, cluttered collection.
Image credit: Wordspun · AI-generated conceptual illustration
Questions about this word
What does "Hashtag" mean?
Hashtag is noun meaning: A keyword phrase marked with # for social media categorization.. A word or phrase preceded by the # symbol, used on social media platforms to categorize content and make it discoverable by others searching for that tag. Hashtags can create movements, signal community, or simply organize content.
Where does the word "Hashtag" come from?
The hash symbol (#) has been on keyboards since the 1960s. The hashtag as social media convention was proposed by Chris Messina on Twitter in 2007 and adopted in 2009.