Short loin is the American name for a cut of beef that comes from the back of the cattle.
[1] It contains part of the spine and includes the top loin and the tenderloin.
This cut yields types of steak including porterhouse, strip steak (Kansas City Strip, New York Strip), and T-bone (a cut also containing partial meat from the tenderloin).
[2] Webster's Dictionary defines it as "a portion of the hindquarter of beef immediately behind the ribs that is usually cut into steaks."
The short loin is considered a tender beef.