Crucifix (4)
I believe the answer is:
rood
'crucifix' is the definition.
(I know that crucifix can be written as rood)
This is all the clue.
(Other definitions for rood that I've seen before include "old piece of land" , "Crucifix on part of an acre" , "Cross, crucifix" , "Old land measure of quarter of an acre" , "Crucifix - old unit of area" .)