ἐχθρός hateful (passively, odious, or actively, hostile); usually as a noun, an adversary (especially Satan)Derivation: from a primary ἔχθω (to hate);KJV Usage: enemy, foe.
Thayer:1) hated, odious, hateful 2) hostile, hating, and opposing another 2a) used of men as at enmity with God by their sin 2a1) opposing (God) in the mind 2a2) a man that is hostile 2a3) a certain enemy 2a4) the hostile one 2a5) the devil who is the most bitter enemy of the divine government
ἐχθρός echthros ekh-thros' From a primary word ἔχθω echthō (to hate); hateful (passively odious, or actively hostile); usually as a noun, an adversary (especially Satan)KJV Usage: enemy, foe.