Concise Bible Dictionary:

πονηοός (from πόνος, ‘labor, sorrow') often refers to the evil nature of the one acting, and the active working out of it. Thus Satan is called that ‘wicked' one. Matt. 13:19, 3819When any one heareth the word of the kingdom, and understandeth it not, then cometh the wicked one, and catcheth away that which was sown in his heart. This is he which received seed by the way side. (Matthew 13:19)
38The field is the world; the good seed are the children of the kingdom; but the tares are the children of the wicked one; (Matthew 13:38)
; Eph. 6:1616Above all, taking the shield of faith, wherewith ye shall be able to quench all the fiery darts of the wicked. (Ephesians 6:16); 1 John 2:13, 14; 3:1213I write unto you, fathers, because ye have known him that is from the beginning. I write unto you, young men, because ye have overcome the wicked one. I write unto you, little children, because ye have known the Father. 14I have written unto you, fathers, because ye have known him that is from the beginning. I have written unto you, young men, because ye are strong, and the word of God abideth in you, and ye have overcome the wicked one. (1 John 2:13‑14)
12Not as Cain, who was of that wicked one, and slew his brother. And wherefore slew he him? Because his own works were evil, and his brother's righteous. (1 John 3:12)
. The demons are evil spirits. Luke 7:21; 8:221And in that same hour he cured many of their infirmities and plagues, and of evil spirits; and unto many that were blind he gave sight. (Luke 7:21)
2And certain women, which had been healed of evil spirits and infirmities, Mary called Magdalene, out of whom went seven devils, (Luke 8:2)
; Acts 19:12, 1612So that from his body were brought unto the sick handkerchiefs or aprons, and the diseases departed from them, and the evil spirits went out of them. (Acts 19:12)
16And the man in whom the evil spirit was leaped on them, and overcame them, and prevailed against them, so that they fled out of that house naked and wounded. (Acts 19:16)
. The same word is used in reference to the man living in sin in the church at Corinth ― "put away.... that wicked person." 1 Cor. 5:1313But them that are without God judgeth. Therefore put away from among yourselves that wicked person. (1 Corinthians 5:13).
κακός, with its many compounds, is a common word for evil and (like πονηρόπς) may apply to the nature or character of those who commit evil, Matt. 21:41; 24:4841They say unto him, He will miserably destroy those wicked men, and will let out his vineyard unto other husbandmen, which shall render him the fruits in their seasons. (Matthew 21:41)
48But and if that evil servant shall say in his heart, My lord delayeth his coming; (Matthew 24:48)
; Phi. 3:2; Rev. 2:22I know thy works, and thy labor, and thy patience, and how thou canst not bear them which are evil: and thou hast tried them which say they are apostles, and are not, and hast found them liars: (Revelation 2:2); as well as to their acts and principles, Mark 7:22And when they saw some of his disciples eat bread with defiled, that is to say, with unwashen, hands, they found fault. (Mark 7:2)1 Cor. 15:3333Be not deceived: evil communications corrupt good manners. (1 Corinthians 15:33); Col. 3:55Mortify therefore your members which are upon the earth; fornication, uncleanness, inordinate affection, evil concupiscence, and covetousness, which is idolatry: (Colossians 3:5); Rom. 1:30; 13:330Backbiters, haters of God, despiteful, proud, boasters, inventors of evil things, disobedient to parents, (Romans 1:30)
3For rulers are not a terror to good works, but to the evil. Wilt thou then not be afraid of the power? do that which is good, and thou shalt have praise of the same: (Romans 13:3)
; 2 Cor. 13:77Now I pray to God that ye do no evil; not that we should appear approved, but that ye should do that which is honest, though we be as reprobates. (2 Corinthians 13:7); though not always with this moral force: see Acts 16:28; 28:528But Paul cried with a loud voice, saying, Do thyself no harm: for we are all here. (Acts 16:28)
5And he shook off the beast into the fire, and felt no harm. (Acts 28:5)
; ‘harm'; and Luke 16:2525But Abraham said, Son, remember that thou in thy lifetime receivedst thy good things, and likewise Lazarus evil things: but now he is comforted, and thou art tormented. (Luke 16:25), ‘evil things.'
πονηρός would in Latin be industriâ malus, malignus. So the enemy of souls is emphatically ὀ πονηρός, "the evil one." κακός in Latin is malus, improbus, &c., and is used in a very general way, opposed to both

Strong’s Dictionary of Greek Words:

apparently a primary word; "foul" or "flawy", i.e. (figuratively) wicked
KJV Usage: