Cut beef spoken of (4)
I believe the answer is:
mown
'cut' is the definition.
('mown' can be a synonym of 'cut')
'beef spoken of' is the wordplay.
'beef' becomes 'moan' (I've seen this before).
'spoken of' shows a homophone (sound like).
'moan' sounds like 'MOWN'.
(Other definitions for mown that I've seen before include "Block of cast metal" , "Cut down with a blade" , "(Of grass) cut" .)