Article about Kipling poem of unaffected simplicity (4)
I believe the answer is:
naif
'unaffected simplicity' is the definition.
(I've seen this before)
'article about kipling poem' is the wordplay.
'article' becomes 'an' (indefinite article).
'about' shows that the letters should be reversed in order.
'kipling poem' becomes 'if' (poem by Rudyard Kipling).
'an' backwards is 'na'.
'na'+'if'='NAIF'
'of' acts as a link.
(Other definitions for naif that I've seen before include "wide-eyed" , "somewhat ingenuous" , "Innocent" , "Unworldly" , "Artless" .)