The headword is aorist, third person singular, of gdoupe/w (an epic/poetic form of doupe/w; see delta 1425, cf. delta 1426, and on initial *gd-, see Lejeune p. 277). The form is presumably quoted from somewhere, but it is attested only here (and in the derivative headword plus gloss in ps.-Zonaras) and, earlier, in Herodian (cf. Etymologicum Magnum 308.54-55).
[1] cf. the D scholia on Homer, Iliad 11.45 (where the plural e)gdou/phsan occurs).
[2] Likewise in the A scholia on that verse.
[3] cf. under epsilon 2310.