Where does “marfóir” come from?

marfóir (Irish) comes from Irish marbh, from Old Irish marbh — dead.

marfóir (Irish): killer

Definitions

Step	Language	Word	Meaning
1	Irish	marbh	dead; defunct; corpse, dead person
2	Old Irish	marbh	dead

marfóir — Etymology, Origin & Word History | Etymology Explorer