Piece of sacred ground (4)
I believe the answer is:
acre
'piece' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'of sacred ground' is the wordplay.
'of' indicates a hidden word.
'ACRE' is hidden in the letters of 'sacred ground'.
Can you help me to learn more?
(Other definitions for acre that I've seen before include "Unit of area of 4,840 square yards" , "marine location in Israel" , "once occupied by Crusaders" , "Imperial land measure" , "Care about the land measure" .)