Source : Webster's Revised Unabridged Dictionary (1913)

Compaction \Com*pac"tion\, n. [L. compactio.]
   The act of making compact, or the state of being compact.
   [Obs.] --Bacon.

Source : WordNet®

compaction
     n 1: an increase in the density of something [syn: {compression},
           {concretion}, {densification}]
     2: the act of crushing [syn: {crush}, {crunch}]

Source : Free On-Line Dictionary of Computing

compaction
     
        {compression}