Teetotalism is the practice of abstinence from alcoholic beverages. A person who practices teetotalism is called a teetotaler.
When asked if he would like something to drink by the Species 8472 Valerie Archer replicant, Commander Chakotay asked for water, prompting Archer to ask if Chakotay was a teetotaler. Chakotay responded that he like to remain in control. (VOY: "In the Flesh")