Tarmenel
From Tolkien Gateway
An Elvish term that clearly translates as 'high heaven', though as it only appears in Bilbo's rhyme quoted above, it's hard to be sure exactly what the term referred to. In Elvish cosmology, the world was enfolded in different layers of airs, and it seems that Tarmenel was a term for the highest or outermost of these - the 'Over-heaven' mentioned later in The Lord of the Rings.