a formal decision not to vote either for or against something in an election or meeting
The government motion was passed by 81 votes to zero with 37 abstentions.
not doing something, especially something that some consider a vice (=an illegal or immoral activity) such as drinking alcohol, taking drugs or having sex
One of the conditions of his release would be abstention from drugs and alcohol.
(US) under the doctrine of abstention, a District Court may decline to exercise or postpone the exercise of its jurisdiction
Abstention from the exercise of federal jurisdiction is the exception, not the rule.