sir·loin 
(sûrloin′)
(sûrloin′)n.
A cut of meat, especially of beef, from the upper part of the loin just in front of the round.
[Middle English surloine, from Old French surlonge, *surloigne : sur, above (from Latin super; see uper in the Appendix of Indo-European roots) + longe, loigne, loin; see LOIN.]