Audibly regretted being cross (4)
I believe the answer is:
rood
'being cross' is the definition.
(term for a crucifix)
'audibly regretted' is the wordplay.
'audibly' shows a homophone (sound like).
'regretted' becomes 'rued' ('rue' can be a synonym of 'regret').
'rued' is a homophone of 'ROOD'.
(Other definitions for rood that I've seen before include "Old land measure of quarter of an acre" , "- Loft; - screen" , "Crucifix - old unit of area" , "Crucifix in church; one quarter of an acre" , "Crucifix on part of an acre" .)