The Collaborative International Dictionary of English v.0.48:

Versus \Ver"sus\, prep. [L., toward, turned in the direction of,
   from vertere, versum, to turn. See Verse.]
   Against; as, John Doe versus Richard Roe; -- chiefly used in
   legal language, and abbreviated to v. or vs.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

30 Moby Thesaurus words for "versus":
   across, adverse to, against, at cross-purposes with, athwart, con,
   confronting, contra, counter to, dead against, en route to, facing,
   fronting, headed for, in conflict with, in front of,
   in opposition to, in passage to, in transit to, on, on route to,
   opposed to, opposite to, over against, to, toward, towards, up,
   upon, vis-a-vis



Bouvier's Law Dictionary, Revised 6th Ed (1856):

VERSUS. Against; as A B versus C D. This is usually abbreviated v.