Lie-in King. The full wording is '...omits up to five letters of the solution'. I think your Lilo is right, without air it would be impossible to relax on.The moon might be Io, with the L and L ignored?
Thanks, Hankir -'Without air it'd be impossible to relax on' sounds a decent description of a LiLo! I found the 10th letter bit easier than tracking down, marking off all the 'omitted from wordplay in the solution' letters. Both aspects were tricky in places!