In the headword phrase, the substantive is a feminine noun in the accusative singular; see LSJ s.v. no/sos, -ou, h(. The infinitive is the present active form from the verb e)/xw, I have or hold; see generally LSJ s.v. The headword phrase is extracted from Euripides' lost tragedy Antiope: see n. 1 below.
[1] Euripides fr. 226 Nauck (and Kannicht). Thus far the passage agrees closely with the entry for the headword phrase in Photius' Lexicon (nu259 Theodoridis) and is identical to Lexica Segueriana 109.17; cf. Bekker 109.17-8.
[2] That is, the feminine noun is modified by a neuter participle, because a disease is a thing. See the comment appended to nu 493.
[3] Thucydides 2.47.3 (web address 1), with scholion. From his celebrated account of the Athenian "plague" of 430 BCE; see OCD(4) s.v. plague, and Adcock, CAH V, pp. 200-2). For Lemnos, an island in the northern Aegean Sea (Barrington Atlas map 56 grid A2), see lambda 452. The exact identity of the pathogen responsible for the pestilence is uncertain, but recent DNA evidence implicates typhoid fever (Papagrigorakis, et al., pp. 206-14).