Sweet things, yet of concern, I fancy (13)
I believe the answer is:
confectionery
'sweet things' is the definition.
(I've seen this before)
'yet of concern i fancy' is the wordplay.
'fancy' indicates anagramming the letters.
'yet'+'of'+'concern'+'i'='yetofconcerni'
'yetofconcerni' is an anagram of 'CONFECTIONERY'.
(Other definitions for confectionery that I've seen before include "sweet things" , "Sweets, chocolate etc" , "Certify on cone (anag)" , "Sweets, chocolates, etc" , "Sugary stuff" .)