A cut of beef (7)
I believe the answer is:
sirloin
'a cut of beef' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for sirloin that I've seen before include "Upper part of loin of beef" , "Choice cut of beef" , "Quality cut of beef loin" , "Type of steak" , "(Knighted?) cut of meat" .)