Strong's #2556: kakos (pronounced kak-os')
apparently a primary word; worthless (intrinsically, such; whereas 4190 properly refers to effects), i.e. (subjectively) depraved, or (objectively) injurious:--bad, evil, harm, ill, noisome, wicked.
Thayer's Greek Lexicon:
́
kakos
1) of a bad nature
1a) not such as it ought to be
2) of a mode of thinking, feeling, acting
2a) base, wrong, wicked
3) troublesome, injurious, pernicious, destructive, baneful
Part of Speech: adjective
Relation: apparently a primary word
Citing in TDNT: 3:469, 391
Usage:
This word is used 51 times:
Revelation 16:2: "earth; and there fell a noisome and grievous sore upon"
