Unaffected (7)
'unaffected' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for natural that I've seen before include "Organic" , "Certainty" , "character on the staff" , "Innate - neither flat nor sharp" , "as one might expect" .)
'unaffected' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for artless that I've seen before include "Without guile or sophistry" , "Naive - unskilful" , "Natural - uncontrived" , "as an empty gallery" , "Simple, unaffected" .)
'unaffected' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for sincere that I've seen before include "(Of person) genuine" , "Genuine; deceit-free" , "Free from pretence" , "Honest, heartfelt" , "devout" .)