1 a (usu. foll. by from) restrain oneself; refrain from indulging in (abstained from cakes and sweets; abstained from mentioning it). b refrain from drinking alcohol.
2 formally decline to use one's vote.
Derivatives:
abstainer n.
Etymology: ME f. AF astener f. OF abstenir f. L abstinere abstent- (as AB-, tenere hold)
Useful english dictionary. 2012.