Creative activities are back in abstract works (4)
I believe the answer is:
arts
'creative activities' is the definition.
(I've seen this before)
'back in abstract works' is the wordplay.
'back' shows that the letters should be reversed in order.
'in' indicates the answer is hidden within the clue.
'stra' is hidden within 'abstract works'.
'stra' reversed gives 'ARTS'.
'are' is the link.
(Other definitions for arts that I've seen before include "A degree" , "Anagram of 19" , "Humanities" , "Literature, music etc." , "Aesthetic creations for a star" .)