Related Clues:

• Closed tight
• Not open
• Opposite of 18-Across
• Isolated, with "off"
• Seal tightly
• Closed tightly
• Slammed, maybe
• Word with ''in,'' ''up'' or ''down''
• Z's
• Not even ajar
• Word with ''up'' or ''down''
• Fastened
• Make it close?
• Securely closed
• See 2 Down