Related Clues:

• Completely closed
• Sealed, say
• Not even cracked
• Securely sealed
• Thus it may get close
• Close to the South you get to 21 down
• This is close
• Close with it
• O, that does not go over the pen
• Open's partner
• Sealed tight
• See 9
• See 17
• See 19
• Close-knit, thus