Source : Webster's Revised Unabridged Dictionary (1913)

Across \A*cross"\ (#; 115), prep. [Pref. a- + cross: cf. F. en
   croix. See Cross, n.]
   From side to side; athwart; crosswise, or in a direction
   opposed to the length; quite over; as, a bridge laid across a
   river. --Dryden.

   {To come across}, to come upon or meet incidentally.
      --Freeman.

   {To go across the country}, to go by a direct course across a
      region without following the roads.

Across \A*cross"\, adv.
   1. From side to side; crosswise; as, with arms folded across.
      --Shak.

   2. Obliquely; athwart; amiss; awry. [Obs.]

            The squint-eyed Pharisees look across at all the
            actions of Christ.                    --Bp. Hall.

Source : WordNet®

across
     adj : placed crosswise; "spoken with a straight face but crossed
           fingers"; "crossed forks"; "seated with arms across"
           [syn: {crossed}] [ant: {uncrossed}]
     adv 1: to the opposite side; "the football field was 300 feet
            across"
     2: in such a manner as to be understood and accepted; "she
        cannot get her ideas across" [syn: {over}]
     3: transversely; "the marble slabs were cut across" [syn: {crosswise},
         {crossways}]