larnax UK /ˈlɑːnæks/US /ˈlɑɹnæks/ noun1 •(historical) A small closed coffin, box or cinerary urn often used as a container for human remains in Ancient Greece.In a chamber tomb at Milatos, Mr. Evans discovered in 1899 a painted larnax or sarcophagus, on which there is figured a great Mycenaean body shield. — 1907 formslarnakes · larnaxes