Area of clear pasturage (3)
I believe the answer is:
lea
'pasturage' is the definition.
(thesaurus)
'area of clear' is the wordplay.
'area of' indicates the answer is hidden within the clue (I've seen this in other clues).
'LEA' is hidden in the letters of 'clear'.
(Other definitions for lea that I've seen before include "area of grassland" , "Field" , "Meadow (poetic)" , "Grass area" , "'The lowing herd wind slowly o'er the . . .'" .)