Some leg of beef (4)
I believe the answer is:
calf
I believe this clue is a double definition.
'some leg' is the first definition.
(I've seen this before)
'beef' is the second definition.
(I've seen this before)
'of' acts as a link.
(Other definitions for calf that I've seen before include "Young animal; part of body" , "Young seal" , "binding?" , "Young cow or bull" , "Fine leather - young whale" .)