The Collaborative International Dictionary of English v.0.48:
Soaker \Soak"er\, n. 1. One who, or that which, soaks. [1913 Webster] 2. A hard drinker. [Slang] --South. [1913 Webster]WordNet (r) 3.0 (2006):
soaker n 1: a heavy rain [syn: downpour, cloudburst, deluge, waterspout, torrent, pelter, soaker] 2: a person who drinks alcohol to excess habitually [syn: alcoholic, alky, dipsomaniac, boozer, lush, soaker, souse]