Source : Webster's Revised Unabridged Dictionary (1913)

Soaker \Soak"er\, n.
   1. One who, or that which, soaks.

   2. A hard drinker. [Slang] --South.

Source : WordNet®

soaker
     n 1: a heavy rain [syn: {downpour}, {cloudburst}, {deluge}, {waterspout},
           {torrent}, {pelter}]
     2: a person who drinks alcohol to excess habitually [syn: {alcoholic},
         {alky}, {dipsomaniac}, {boozer}, {lush}, {souse}]