Derived from scholia to Homer, Iliad 4.177, where the headword -- present participle, masculine nominative singular, with the original iota (e)piqrw/|skwn) which was unpronounced and written subscript in later ages -- occurs (web address 1).
Same entry in the Synagoge, Lexica Segueriana 229.24, and Photius, Lexicon pi1559; similar one (for the finite verb) in Hesychius epsilon4714, and cf. epsilon4715.