1. Unable to focus one's attention on something; distracted, preoccupied, or otherwise unable to take a proper, productive interest in something. A: "I've been feeling a little spaced at work lately." B: "Something on your mind? Is everything OK at home?" My parents are so spaced out, they'll never even notice that I was gone for the night.

2. Confused, disoriented, or stupefied, from or as from drug use. Getting knocked in the head like that left me pretty spaced out. You seem really spaced. Have you been smoking reefer again?