The Collaborative International Dictionary of English v.0.48:

Teetotaler \Tee*to"tal*er\, n.
   One pledged to entire abstinence from all intoxicating
   drinks.
   [1913 Webster]

WordNet (r) 3.0 (2006):

teetotaler
    n 1: a total abstainer [syn: teetotaler, teetotaller,
         teetotalist]

The Devil's Dictionary (1881-1906):

TEETOTALER, n.  One who abstains from strong drink, sometimes totally,
sometimes tolerably totally.