Related Clues:

• Q: 'When is a door not a door?' A: 'When it's ___'
• Closed to some extent
• Allowing a peek, in a way
• Allowing a draft, e.g.
• Not exactly closed
• Open a wit
• Cracked a little
• Admitting air
• Slightly open, as a door
• Cracked slightly
• Allowing a draft
• Enabling eavesdropping, perhaps
• Not closed
• Not closed all the way
• Like a door, when it's not a door, in a riddle