From Late Latin decapitāre — literally 'to un-head' — from dē- (off) + caput (head), PIE *káput. While its cousins capital, cattle, captain, and chapter all abstracted 'head' into metaphors for wealth and leadership, decapitate kept the visceral, physical meaning. The French Revolution made it ubiquitous.
To cut off the head of; to behead.
From Late Latin 'decapitāre' (to behead), composed of 'dē-' (off, away from) + 'caput' (head, genitive 'capitis'), from PIE *kaput- (head). The word literally means 'to un-head' or 'to remove the head from.' Latin 'caput' is one of the best-attested PIE roots, producing an enormous family: 'capital' (pertaining
'Capital punishment' and 'decapitate' share the same root and the same logic: Latin caput (head). Capital punishment originally meant punishment affecting the head — execution. Meanwhile, the rest of the *káput family abstracted away: heads of cattle became wealth, wealth became capital, capital became capitalism