harmless vs benign

harmless and benign both are adjectives.

Word	Noun	Adjective	Verb	Adverb
harmless	No	Yes	No	No
benign	No	Yes	No	No

harmless (adjective)	benign (adjective)
not causing or capable of causing harm	pleasant and beneficial in nature or influence
	not dangerous to health; not recurrent or progressive (especially of a tumor)
	kindness of disposition or manner