Also known as: 失神, 晕厥, 昏厥
Becoming Unconscious and passing out due to mental shock, Asphyxiation, blood loss, etc.
The medical term is "syncope", which refers to the brain not getting enough blood and temporarily shutting down, recovering in a few seconds when it gets enough blood. For Danbooru however, fainting refers simply to the act of becoming limp and collapsing.
Also applies to a character that has fainted, though not to be confused with Sleeping.