Quenya 

telluma

dome, copula

telluma noun "dome, copula", especially the "Dome of Varda" over Valinor, but also applied to the domes of the mansion of Manwë and Varda upon Taniquetil. Adopted from Valarin _delgūmā under the influence of pure Quenya telumë (WJ:399, 411). Pl. tellumar is attested (Nam, RGEO:66)_.