Decapitation

Decapitation was the act of removing an individual's head.

Blon Fel-Fotch Passameer-Day Slitheen killed Mr. Cleaver by decapitating him. While disguised as a human, she claimed that he slipped on "a very icy patch". (DW: Boom Town)

Time Lords could still regenerate after being decapitated. Cavisadoratrelundar was decapitated and only killed after being stabbed in both her hearts. (EDA: The Shadows of Avalon)

A suicide bomber that was still living (due to Miracle Day) even after blowing himself up was still conscious even after his head was detached. (TW: The New World)

Members of the Order of the Headless were decapitated in their initiation. Their heads remained mobile, even after rotting into skulls. (DW: A Good Man Goes to War, DW: The Wedding of River Song)