[1] Likewise or similarly in other lexica; references at Photius upsilon328 Theodoridis. The headword infinitive itself is regarded as coming from Sophocles (fr. 1106 Radt, contextless).
[2] (This addendum to the entry is lacking in manuscripts AFV, and Adler indicates it to be an interpolation.) On u(yau/xhn (sic: accented paroxytone), a two-termination adjective, see generally LSJ s.v.; it is attested with (e.g.) the masculine noun 'horse' in Plato, Phaedrus 253D, and -- figuratively -- with the feminine noun 'fir-tree' in Euripides, Bacchae 1061.