Pleased about fields (4)
I believe the answer is:
leas
'fields' is the definition.
(I've seen this before)
'pleased about' is the wordplay.
'about' indicates a hidden word.
'LEAS' is hidden in the letters of 'pleased'.
(Other definitions for leas that I've seen before include "Fields suitable for grazing by livestock" , "Arable or pasture lands" , "meadows" , "in which flowers might be found" .)