“Skill in figuring out how someone or something died. Higher skill allows more details to be determined and more difficult organisms to be examined.
Pathology is a skill that is raised once you have an Autopsy Kit in your inventory and start examine the corpse of slain creatures (whether you killed them yourself or not).
Examining corpses left behind by other players can be amusing sometimes, as the name of the player and the cause of death of the creature is indicated.
See Anatomy.