εἰκόσορος

ον, Subst., ἡ

εἴκοσι, ἐρέσσω

A. with twenty oars, Od. 9.322, Teles p.27 H., AP 5.203.10 (Mel.), 6.222 (Theodorid.): as Subst., εἰ. (sc. ναῦς), ἡ, D. 35.18.
Liddell, Scott & Jones
A Greek-English Lexicon, 1940
An open-access project