Source : Webster's Revised Unabridged Dictionary (1913)

Surloin \Sur"loin`\, n. [F. surlonge; sur upon + longe loin. See
   {Sur-}, and {Loin}.]
   A loin of beef, or the upper part of the loin. See {Sirloin},
   the more usual, but not etymologically preferable,
   orthography.