The manuscript version of the Early Qenya Grammar (EQG) of the 1920s had ᴱQ. yundóra “two million” (PE14/50), but in the typescript version this became ᴱQ. yundóre “billion” (PE14/83), a combination of ᴱQ. yúyo “two” and the “-illion” suffix ᴱQ. -(n)dóre.

Neo-Quenya: I would retain ᴺQ. yundórë “billion” for purposes of Neo-Quenya, as we have no better alternatives. Compare later Q. yucainen “twenty” = “*double ten”.