bad, evil, harm, ill, noisome, wicked

Concise Bible Dictionary:

Both πονηρός and φαῦλος are translated ‘evil,' but their application in scripture is different, though they may seem to blend. Φαῦλος occurs but four times, referring to doing evil, John 3:20; 5:29; and to the character of what is done as being evil. Titus 2:8; Jas. 3:16.
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, 38; Eph. 6:16; 1 John 2:13, 14; 3:12. The demons are evil spirits. Luke 7:21; 8:2; Acts 19:12, 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. 5:13.
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; 24:48; Phi. 3:2; Rev. 2:2; as well as to their acts and principles, Mark 7:21 Cor. 15:33; Col. 3:5; Rom. 1:30; 13:3; 2 Cor. 13:7; though not always with this moral force: see Acts 16:28; 28:5; ‘harm'; and 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
καλός and ἀγαθός,good' 3 John 1:11 Both κακός and πονηρός occur in Rev. 16:2: "noisome (κα.) and grievous (πο.)"; and their nouns κακία and πονηρία, "malice and wickedness." 1 Cor. 5:8.

Strong’s Dictionary of Greek Words:

apparently a primary word; worthless (intrinsically, such; whereas 4190 properly refers to effects), i.e. (subjectively) depraved, or (objectively) injurious
KJV Usage:
bad, evil, harm, ill, noisome, wicked