Related Clues:

• Word on a check
• Invalidate, as a check
• Null and ___
• Blank space
• Null and --
• "___ where prohibited"
• Loosened, as a 57-Down
• It's got nothing
• Opened, as a necktie
• Tear up, as a check
• Not occupied
• Empty like space
• Null and empty
• Containing nothing or not legally binding
• Empty space or vacuum