Source : Webster's Revised Unabridged Dictionary (1913)

Athwart \A*thwart"\, prep. [Pref. a- + thwart.]
   1. Across; from side to side of.

            Athwart the thicket lone.             --Tennyson.

   2. (Naut.) Across the direction or course of; as, a fleet
      standing athwart our course.

   {Athwart hawse}, across the stem of another vessel, whether
      in contact or at a small distance.

   {Athwart ships}, across the ship from side to side, or in
      that direction; -- opposed to {fore and aft}.