Definitions for: Sirloin

[n] the portion of the loin (especially of beef) just in front of the rump

Webster (1913) Definition: Sir"loin`, n. [A corruption of surloin. Not so called
because this cut of beef was once jocosely knighted (dubbed
Sir Loin) by an English king, as according to a popular
story.]
A loin of beef, or a part of a loin. [Written also
surloin.]

See Also: beef loin, cut, cut of meat, flat bone, pin bone, sirloin steak, sirloin tip, wedge bone