ἕρμα ἕρμα, ατος, τό, a prop, support, used to keep ships upright when ashore, Il.: metaph. of men, ἕρμα πόληος prop or stay of the city, Lat. columen, Hom.; μελαινέων ἕρμʼ ὀδυνάων, of a sharp arrow, the foundation, i. e. the cause, of pangs, Il. a sunken rock, reef, on which a vessel may strike, Hdt., Aesch., etc. a mound, cairn, barrow, Soph. that which keeps a ship steady, ballast, Plut. deriv. uncertain