A person who chooses to refrain from something, especially someone who doesn't drink alcohol.
From abstain + -er (agent suffix indicating one who performs an action or has a characteristic). The suffix -er creates nouns for people engaged in an activity.
The 19th-century temperance movement created millions of self-identified 'abstainers,' and this identity was so strong it shaped entire communities—some towns were even founded specifically for people who abstained from alcohol.
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