The Collaborative International Dictionary of English v.0.48:

Abut \A*but"\, v. i. [imp. & p. p. Abutted; p. pr. & vb. n.
   Abutting.] [OF. abouter, aboter; cf. F. aboutir, and also
   abuter; a (L. ad) + OF. boter, buter, to push: cf. F. bout
   end, and but end, purpose.]
   To project; to terminate or border; to be contiguous; to
   meet; -- with on, upon, or against; as, his land abuts on the
   road.
   [1913 Webster]

WordNet (r) 3.0 (2006):

abut
    v 1: lie adjacent to another or share a boundary; "Canada
         adjoins the U.S."; "England marches with Scotland" [syn:
         border, adjoin, edge, abut, march, butt, butt
         against, butt on]