No language indication in the Etymologies, but Noldorin from context and phonological evidence
Noldorin
nûr
adjective. deep
nûr
noun. race
nûr
adjective. deep
nûr
noun. race
nurnen
place name. Nurnen
gûr
noun. death
núron
masculine name. Ulmo
beor
noun. follower, vassal
bior
noun. follower, vassal
dem
adjective. sad, gloomy
guruth
noun. death
guruth
noun. death
gwanath
noun. death (act of dying, not death as a state or abstract)
gwanw
noun. death (act of dying, not death as a state or abstract)
noer
adjective. sad, lamentable
path
adjective. smooth
path
adjective. smooth
tû
noun. muscle, sinew, vigour, physical strength
uiar
masculine name. Ulmo
Noldorin name of ᴹQ. Ulmo from The Etymologies from the 1930s (Ety/WAY), also appearing as Guiar (Ety/ULU), derived from the primitive form ᴹ✶Wāyārō.
Conceptual Development: In the Gnomish Lexicon from the 1910s, his name was given as G. Gulma (GL/18, 43), but appears as Ulm or Ulum in “Official Name List” for the Lost Tales (PE13/101). In the Lays of Beleriand from the 1920s, his name was first given as Gulma but was revised to ᴱN. Ylmir (LB/93), a form that reappeared in the earliest Silmarillion drafts (SM/13).
A Noldorin name for Ulmo appearing only in The Etymologies from the 1930s (Ety/NU), apparently a masculinized form of nûr “deep” and with the suffix -on.