1. most absent-minded, dreamy, or mentally unfocused
Usage: informal; superlative form of ‘spacey’

Examples

• She’s the spaciest person I know, always forgetting where she put her keys.
• During finals week, he became even spacier than usual.
• That was the spaciest thing you could have said during the meeting.
• The spaciest student in class finally remembered to bring her textbook.
• After staying up all night, I felt like the spaciest person alive.
• He gave me the spaciest look when I asked about the homework.