The Collaborative International Dictionary of English v.0.48:
Decapitation \De*cap`i*ta"tion\, n. [LL. decapitatio: cf. F. d['e]capitation.] The act of beheading; beheading. [1913 Webster]WordNet (r) 3.0 (2006):
decapitation n 1: execution by cutting off the victim's head [syn: decapitation, beheading] 2: killing by cutting off the head [syn: decapitation, beheading]