v.1. To organize or arrange some things or some people with spaces between: The tournament organizers spaced the matches out so that players would have time to rest. The police officers spaced themselves out along the parade route.
2. To stupefy or disorient someone from or as if from a drug: The medicine spaces me out so I can't think clearly. The summer heat tends to space out the students and makes it difficult to teach.
3. To lose awareness of one's surroundings: I stared out the window and spaced out for an hour.
4. To lose concentration or become inattentive: I was supposed to meet her at 9:00, but I spaced out and didn't get there till 10:30.