Rare term for beheading or decapitation, typically encountered in historical, literary, or dramatic settings rather than everyday conversation.
In period dramas, the beheading of a criminal is sometimes depicted.
斬新 shares the kanji 斬 but means 'novel/original' and has nothing to do with the beheading sense of 斬.
novel; original; innovative; cutting-edge
decapitation; beheading · decapitated head; severed head
killing with a blade; slaying; putting to the sword
killing a villain; executing a wrongdoer
slash; slashing attack
The kanji 斬 means 'to cut' or 'to behead'. The reading ざん is the on'yomi, used in compounds. As a standalone noun, it is rare and literary.