Related Clues:

• Exterior or external, like space
• This space is beyond earth's atmosphere
• Optional item as supplement or increment
• Something attached
• Very slight in amount, at the edge
• A twisted route isn't in it!
• One might get to rue this in no 7 down way
• It might be more off-centre so to rue this
• Seems it's less in here
• There's nothing inside this to make it round and true
• Sounds as if there's no inn there
• O, true, there's less in that
• O, it gets to be true that one is not in this
• This route does not get one to the centre
• No tin skin