sirloin tip vs cut of beef

sirloin tip and cut of beef both are nouns.

Word	Noun	Adjective	Verb	Adverb
sirloin tip	Yes	No	No	No
cut of beef	Yes	No	No	No

As nouns, cut of beef is a hypernym of sirloin tip; that is, cut of beef is a word with a broader meaning than sirloin tip:

sirloin tip (noun)	cut of beef (noun)
a cut of beef from the upper end of the sirloin	cut of meat from beef cattle