v.1. To prevent something from being seen: The smoke from the volcano blocked out the sun. This Internet filter blocks obscene language out.
2. To deliberately forget or stop thinking about something, especially something that is unpleasant: She blocked out the horrible details of the accident. The memories of his childhood were painful, and he blocked them out as much as he could.
3. To lay out or present the details of something: The director blocked out the actors' movements on stage. The city council blocked the new budget out.