Tarmenel

Tarmenel, or Tar-menel was a term that refers to the "true" or "upper" firmament.

The term appears Bilbo's Song of Eärendil which he recites in Rivendell.

There flying Elwing came to him,
and flame was in the darkness lit;
more bright than light of diamond
the fire upon her carcanet.
The Silmaril she bound on him
and crowned him with the living light,
and dauntless then with burning brow
he turned his prow; and in the night
from Otherworld beyond the Sea
there strong and free a storm arose,
a wind of power in Tarmenel;
by paths that seldom mortal goes
his boat it bore with biting breath
as might of death across the grey
and long-forsaken seas distressed:
from east to west he passed away.

In Myths Transformed it is described as the "true firmament", of which Nur-menel, the Dome of Varda, was a simulacrum.

In the unfinished index, Tolkien defines the term as "high heaven, region of wind".^:216

Etymology

Tarmenel is a Quenya name, described as signifying "true firmament", apparently consisting of tar + menel.