The Collaborative International Dictionary of English v.0.48:

Overrun \O`ver*run"\, v. t. [imp. Overran; p. p. Overrun; p.
   pr. & vb. n. Overrunning. ]
   1. To run over; to grow or spread over in excess; to invade
      and occupy; to take possession of; as, the vine overran
      its trellis; the farm is overrun with witch grass.
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            Those barbarous nations that overran the world.
                                                  --Spenser.
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   2. To exceed in distance or speed of running; to go beyond or
      pass in running.
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            Ahimaaz ran by the way of the plain, and overran
            Cushi.                                --2 Sam.
                                                  xviii. 23.
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   3. To go beyond; to extend in part beyond; as, one line
      overruns another in length.
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   Note: In machinery, a sliding piece is said to overrun its
         bearing when its forward end goes beyond it.
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   4. To abuse or oppress, as if by treading upon.
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            None of them the feeble overran.      --Spenser.
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   5. (Print.)
      (a) To carry over, or back, as type, from one line or page
          into the next after, or next before.
      (b) To extend the contents of (a line, column, or page)
          into the next line, column, or page.
          [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

33 Moby Thesaurus words for "overrunning":
   alluvion, alluvium, cataclysm, deluge, diffusion, engulfment,
   flood, imbuement, infestation, inundation, invasion, lousiness,
   overflow, overflowing, overspreading, overswarming, penetration,
   permeation, pervasion, plague, ravage, spill, spillage, submersion,
   suffusion, swarm, swarming, teeming, the Deluge, the Flood,
   transfusion, washout, whelming