ἔχμα (ἔχω), pl. ἔχματα:
props, supports, bearers;
νηῶν, πύργων, Ξ 410, Il. 12.260; of the earth under a mass of
rock, πέτρης, Il. 13.139; also of the mud or rubbish from a canal,
holding back the flow of water, Il. 21.259.