Slash
From CGWiki
Slash is slang for fan-pairings of characters or people from popular culture such as movies, TV shows, bands, etc. A predominant amount of slash is of the boy/boy or yaoi variety, though other gender pairings also exist. Much of slash fanfiction or fanart depicts sex scenes, though whether it's soft or hardcore is up to the author.
Serious slash fiction is believed to have originated in the Star Trek fan community.
Notable and infamous slash pairings include: Kirk/Spock (Star Trek), Heero/Quatre (Gundam Wing) and Harry/Draco/Snape/Hagrid/Sorting Hat (Harry Potter).

