The story
Blend of fan + adventure, in reference to MS Paint Adventures, the website that hosted Homestuck until 2018.
Etymology from Wiktionary, CC BY-SA 4.0.
fanventure
Today it means: A webcomic in the style of Homestuck, usually taking place in the same universe and featuring many of the same gimmicks, such as sprite art, reader-submitted commands, and lengthy animations. Full definition →