Fruitless sort of raid (4)
I believe the answer is:
arid
'fruitless' is the definition.
(I've seen this in another clue)
'sort of raid' is the wordplay.
'sort of' indicates anagramming the letters.
'raid' with letters rearranged gives 'ARID'.
(Other definitions for arid that I've seen before include "Tedious; short of rain" , "Rainless (region)" , "Without much rainfall" , "Dry and infertile" , "Extremely dry" .)