Genderswap, or sometimes also "Genderfuck", means any kind of story in which a character changes their gender.
The convention is to refer to the characters in the form Girl!Dean or Girl!Sam. There are two main types of fic in this genre either Sam and/or Dean waking up as a girl as a result of some supernatural intervention, or stories where either Sam and/or Dean have always been female. There are are actually about a character being transgender or non-binary.
- See Crack page for a list of Genderswap stories.