621
In real, traceable use. Part of the curated seed collection; community review is coming.
Sense 1
Meaning · English
e621.net, a chiefly pornographic furry booru digital art website.
Register: slang
Where it’s used:
Used
American English
Examples
Is there a tag on 621 that describes this interaction and/or her emotional state? Or maybe a site/page that collects similar stuff? I want moar. Not even necessarily furry, if that's too rare.
Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30)
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).
Sense 2
Meaning · English
21 June (abbreviated 6/21 in the United States), as an occasion to celebrate the website by posting furry-related pornography (yiff) online.
Register: slang
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).
Common questions
What does “621” mean?
e621.net, a chiefly pornographic furry booru digital art website.
Is “621” formal or informal?
621 is generally slang.