1. Third person singular present indicative of 'abster-se' - to refrain or desist from something; to choose not to participate
He abstains from voting on this matter.
Ele abstém-se de votar nesta questão.
2. To refrain from consuming or using something, particularly alcohol or food
She abstains from alcohol for health reasons.
Ela abstém-se de álcool por razões de saúde.