Some sympathetic article ... (3)
I believe the answer is:
the
'article' is the definition.
(the definite article in English)
'some sympathetic' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'THE' is hidden in the letters of 'sympathetic'.
(Other definitions for the that I've seen before include "Finis" , "French drink" , "and 24 Down: Similar things" , "The most frequently occurring word in the Bible (and in this clue!)" , "Base of ever-expanding nursery rhyme" .)