mulo

noun. dust, dust, [ᴱQ.] fine powder

A word in the Declension of Nouns from the early 1930s glossed “dust”, given as an example of declensions for nouns that in ancient times ended with short -ŭ: mulǔ- (PE21/10-11). It is probably a later iteration of ᴱQ. mul (muld-) “fine powder” from the Qenya Lexicon of the 1910s, a derivative of the early root ᴱ√MULU “grind (fine)” (QL/63). In notes from the late 1950s or early 1960s, Tolkien gave Q. mulë for “meal” = “✱coarsely ground flour”, so it seems ✱√MUL “grind” either survived or was restored. For purposes of Neo-Eldarin, I think it is appropriate to use this word with the earlier sense “fine powder” as well.

asto

noun. dust

A noun in The Etymologies of the 1930s glossed “dust” derived from the root ᴹ√ÁS-AT (Ety/ÁS-AT). It was also mentioned in The Feanorian Alphabet from the late 1930s with the same form and meaning (PE22/21-22), and in the revisions of that document from the 1940s, though there it was replaced with ᴹQ. osto as a name for one of the tengwar (PE22/50). This replacement may only have to do with tengwar names, and doesn’t necessarily invalidate asto “dust”.