The headword is otherwise unattested, though Adler cites for comparison the unedited lexicon of Codex Laurentianus 59.16.
Bernhardy suggested that it might be the same as 'Elbessos', which (uniquely) appears as the name of a river in Theognostus, Canones 402. (Barrington Atlas Map 65 grid C4 shows a town of this name in the mountains of Lycia; there is a lake nearby, but no river.)