See on Rev 12:3. The word is commonly derived from ἔδρακον, the second aorist tense of δέρκομαι to see clearly, in allusion to the sharp sight of the fabled dragon.
Old (ἀρχαῖον)
See on 1Jo 2:7.
The Devil
Note the three epithets: the Old Serpent, the Devil, Satan. See on Mat 4:1; see on Luk 10:18.