[1] = Lexicon Ambrosianum 82, according to Adler. In fact two cities of this name are known: one on the Asiatic shore of the Hellespont (Barrington Atlas map 51 grid G4; present-day Maltepe) and Abydos/Ebot in Upper Egypt (Barrington Atlas map 77 grid F4); without much doubt, the former is meant here. (In Hesychius alpha23 the gloss is fuller -- 'a Trojan city of the Hellespont'. Latte regards the entry as prompted by Homer, Iliad 2.836, accusative case, although similar wording appears in a late scholion to Iliad 17.584, where the adverbial derivative *)abudo/qi appears -- see n. 3 below). See also alpha 100, sigma 465, and generally OCD(4) s.v.
[2] = the first sentence of Pausanias the Atticist alpha3 and Photius alpha63 Theodoridis; cf. also Zenobius 1.1, s.v. *)abudhno\n e)pifo/rhma (alpha 100), and Kassel-Austin, PCG III.2 p.376 on Aristophanes fr. 755. See generally sigma 1330, sigma 1331, sigma 1332.
[3] Probably from commentary to Homer, Iliad 17.584, the only literary attestation of this adverb prior to Musaeus Grammaticus (5/6 CE); cf. Apollonius Dyscolus On Adverbs 2.1.1.164.
[4] = Synagoge Codex B alpha44, but in the better mss of Photius (Lexicon alpha64 Theodoridis) the adjective (in a nominative-case entry) is a)/buqos ('bottomless'), surely correctly; cf. alpha 104. The ultimate source may be Plato, Parmenides 130D, though there too the text is uncertain: perhaps ei)/s tin' a)/buqon fluari/an (web address 1), though the alternatives include ei)/s tina bu=qon fluari/as. On the adjective a)/buqos, a synonym for a)/bussos, see the LSJ entry at web address 2.
[5] There are many literary attestations of this form of the ethnic adjective (nominative singular masculine), beginning with Herodotus 4.138. For an instance in the Suda see pi 71.