Not harsh or violent (6)
I believe the answer is:
gentle
'not harsh or violent' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for gentle that I've seen before include "amiable" , "Soothing - light" , "Mild-mannered" , "Jane Eyre's kind person with a book? -- eternal greed (anag)" , "Mild and benign" .)