decapitation

Examples from literature

He went, and finding the gates of hell open, dragged the queen by her hair from the throne, and was about to decapitate her, but she mollified him by her prayers and saved her life by becoming his wife. 
They came across a number of snakes, and decapitated the reptiles with their hoes, and afterwards hung them all up—tied together by the tail—to a bough. 
Walls and faded wall-paintings, limbs of decapitated goddesses gleaming white through the grass and rioting weeds, tottering columns, arches, and vaults, and deserted galleries receding in endless perspective, leaped out lifelike on a background of night and storm. 

decapitate | American Dictionary

decapitate
verb[ T ]
us/dɪˈkæp·ɪˌteɪt/
to cut off the head of a person or animal