decapitation (as a punishment)
Refers specifically to execution by beheading, often in historical or legal contexts.
Decapitation was a punishment once carried out in many countries.
Compound of 斬首 (ざんしゅ, 'beheading') and 刑 (けい, 'punishment'). The exact historical derivation is uncertain, but the term is a straightforward Sino-Japanese legal compound.