The headword is the nominative singular form of the noun. Of the three quotations that follow only the last presents the word in this form; in the other two cases the word appears in the accusative singular. The lexicographical information (see n. 1 below) perhaps derives from commentary to Herodotos 7.38 (web address 1), where we find one of the only other non-lexicographical attestations of this form. See also mu 475, where the plural form is glossed and ascribed specifically to Herodotos.
[1] cf. Hesychius mu669, mu670; ps.-Herodian 213; Glossae in Herodotum mu3; Synagoge, Photius mu228 Theodoridis, and ps.-Zonaras 1339. Adler also cites the unpublished Ambrosian Lexicon (305). Cf. delta 461 gloss; kappa 1485 end.
[2] Aelian fr. 72 Hercher, 75 Domingo-Forasté; an abridgment of part of a passage quoted at greater length at eta 350.
[3] Eunapius fr.94 FHG (4.54), 88 Blockley (1983: 124-5). Kuster preferred e)tw=n (genitive plural of 'kinsmen') over e)qw=n ('customs').
[4] Here the Suda uses the feminine accusative singular i(e/reian, referring back to gunai=ka/ tina in the prior fragment.
[5] Aelian fr. 119 Hercher (122 Domingo-Forasté). On Nero (Roman emperor 54-68 CE) cf. nu 254 and OCD(4) s.v. This passage concerns Nero's sojourn in Greece, beginning in September 66, where he performed in musical concerts and the Olympic Games, and pronounced the freedom of the Greeks in November 67. The emperor had delegated control over Roman affairs to his freedman Helius; cf. Suetonius, Nero 22-24 (web address 2); Cassius Dio 62.12; Henderson (1908): 382ff; Champlin (2003): 53-61.