A preposition appearing in the A Elbereth Gilthoniel prayer in the phrase le nallon sí di’nguruthos (LotR/729). This phrase is loosely translated as “here overwhelmed in dread of Death I cry” (RGEO/64; PE17/21). However, Tolkien gave a more exact translation “to thee I cry here beneath-death-horror” (RGEO/64), and said that di actually means “beneath, not touching, under” as a derivative of primitive ✶ndī (PE17/95).

Conceptual Development: The Etymologies of the 1930s had N. di “in” under the root ᴹ√NDI/DI of the same meaning as ᴹ√MI [“in”] (EtyAC/NDI). This entry had a brief phrase {ni >>} di ngorgoros, probably an early draft of A Elbereth Gilthoniel. Thus the “loose” translation “in dread of death” may have been Tolkien’s original intended meaning; compare N. Gorgoroth “Deadly Fear” (Ety/ÑGOROTH).

It seems that sometime in the 1960s Tolkien changed his mind on the meaning of di. He initially toyed with connecting it to Q. lé “with”, but changed his mind to the derivation from ✶ndī “beneath” as given above (PE17/95). This is meaning he gave to di in the song-cycle The Road Goes Ever On published in 1967 (RGEO/64).

Earlier still, the Gnomish Lexicon of the 1910s had di as the definite variant of the preposition G. da (GL/29). Tolkien specified the preposition was used with the “allative only”, but its gloss was hard to read, either “with” or maybe “into”. This preposition appeared in the full Gnomish title of the Lexicon itself: i·Lam na·Ngoldathon “Goldogrin” di Sacthoðrin, untranslated but perhaps meaning “*the Language of the Gnomes ‘Goldogrin’ [translated] into English”, or “*with English [translations]”.