- 1: being of one mind : agreeing
- 2: formed with or indicating unanimity : having the agreement and consent of all
Unanimity is complete agreement by all people in a given situation. When unanimous, everybody is of same mind and acting together as one. Many groups consider unanimous decisions a sign of agreement, solidarity, and unity. Unanimity may be assumed explicitly after a unanimous vote or implicitly by a lack of objections.
Practice varies as to whether a vote can be considered unanimous if some voter abstains. Robert's Rules of Order allows unanimity even with abstentions, equating "unanimous consent" with "silent consent", i.e. with no objections raised. In contrast, a United Nations Security Council resolution is not considered "unanimous" if a member abstains. In the European Union, the Treaty of Amsterdam introduced the concept of "constructive abstention", where a member can abstain in a vote where unanimity is required without thereby blocking the success of the vote. This is intended to allow states to symbolically withhold support while not paralysing decision-making.