For the headword see already mu 1308; and for the the headword with this gloss cf. again under mu 1310. It is a feminine abstract noun in the nominative (and vocative) singular; cf. other cognates at mu 1307 and mu 1311. In the quotation which follows, the adjectival form, moxqhro/s, -a, -on, appears in the genitive plural.
As Adler notes, Wentzel attributed this material to an early rhetorical lexicon used by the Suda's compilers (Adler, p. xvii; Wentzel, pp. 477-487). It is apparently the source of Bekker's Fifth Lexicon, the Lexeis Rhetorikai (Bekker, pp. 195-318).
[1] So too Etymologicum Magnum 592.3.
[2] Lycurgus (ca. 390-324 BCE; Develin, person no. 1832) was an Athenian politician; OCD(4) s.v. Lycurgus(3) and lambda 825. He initiated impeachment (ei)saggeli/a: cf. epsiloniota 220 and epsiloniota 221) proceedings in the Assembly, and--together with another Athenian citizen, a certain Ariston--later prosecuted Lycophron (n. 3) on a charge of treason, manifested--the prosecution had to prove--in seduction. The trial probably took place in 333 BCE (Whitehead, p. 81).
[3] Lycurgus fr. 63 Conomis. To the defense of Lycophron (Develin, person no. 1828) arose the renowned orator and politician Hyperides (389-322 BCE; Develin, person no. 1437; OCD(4) s.v., upsilon 294, and upsilon 295). The defendant, a wealthy Athenian horsebreeder, had for three years been stationed as hipparch on the island of Lemnos (northeast Aegean Sea; see generally lambda 448 and cross-references there) at the time of his indictment; cf. Hyperides, In Defense of Lycophron 16-17 (web address 1). The verdict in the case is unknown (Whitehead, pp. 82-3).