The Collaborative International Dictionary of English v.0.48:
Sur- \Sur-\ [F. sur over, above, contr. fr. L. super, supra. See
A prefix signifying over, above, beyond, upon.
Hitchcock's Bible Names Dictionary (late 1800's):
Sur, that withdraws or departs; rebellion
Bouvier's Law Dictionary, Revised 6th Ed (1856):
SUR. A French word which signifies upon, on. It is very frequently used in
connexion with other words as, sur rule to take deposition, sur trover and
conversion, and the like.