[1] Same equivalence in other lexica; references at Photius alpha309 Theodoridis. The headword, presumably quoted from somewhere (there numerous possibilities), is masculine accusative singular or neuter nominative/accusative singular of the adjective (also used as a substantive, as the present entry illustrates) a)gwgo/s; see LSJ s.v.
[2] George of Pisidia, Heraclius' Expedition 3 fr. 49 Tartaglia. As Tartaglia notes (236, n.95), the Pisidian's fragments 48-53 relate to the final weeks of Chosroes II's rule up until his overthrow and execution on February 28, 628. See next note and related entries at alpha 1510 and upsilon 204.
[3] On Chosroes II, see generally chi 418 note.
[4] Masculine accusative plural of the headword, again extracted from somewhere -- perhaps Thucydides 2.12.2, which generated scholiastic comment.