Cut of meat's a joke (3)
I believe the answer is:
rib
'a joke' is the definition.
(I've seen this before)
'cut of meat's' is the wordplay.
'cut of' means to remove the last letter (I've seen 'cut' mean this).
'meat's' becomes 'ribs' (rib is a kind of meat).
'ribs' with its final letter taken away is 'RIB'.
(Other definitions for rib that I've seen before include "Hinged rod in umbrella" , "Tease; pectoral bone" , "spare one?" , "Poke fun at the bone" , "Chest bone, may be floating" .)