The Collaborative International Dictionary of English v.0.48:

Teetotalism \Tee*to"tal*ism\, n.
   The principle or practice of entire abstinence, esp. from
   intoxicating drinks.
   [1913 Webster]

WordNet (r) 3.0 (2006):

teetotalism
    n 1: abstaining from alcohol [syn: teetotaling, teetotalism]