The Collaborative International Dictionary of English v.0.48:

alcoholism \al"co*hol*ism\ ([a^]l"k[-o]*h[o^]l*[i^]z'm), n. [Cf.
   F. alcoolisme.]
   1. (Med.) Chronic excessive drinking of alcoholic beverages
      that leads to social, occupational, psychological and
      physiological problems.
      [AS]

   2. (Med.) Psychological and physiological dependence on
      alcohol; sudden cessation of drinking may lead to
      withdrawal symptoms.
      [AS + PJC]

WordNet (r) 3.0 (2006):

alcoholism
    n 1: habitual intoxication; prolonged and excessive intake of
         alcoholic drinks leading to a breakdown in health and an
         addiction to alcohol such that abrupt deprivation leads to
         severe withdrawal symptoms [syn: alcoholism, alcohol
         addiction, inebriation, drunkenness]
    2: an intense persistent desire to drink alcoholic beverages to
       excess [syn: dipsomania, alcoholism, potomania]