A word appearing as ruive “wild fire — fire as conflagration” in etymological notes from around 1964 (DD), along with a longer variant aparuive (PE17/183). The short form ruive is derived from the root √RUYU “blaze (red)”, but it is not clear what the apa- prefix means in the longer form.

Conceptual Development: In the Qenya Lexicon of the 1910s there was a noun ᴱQ. (uru)purnie “conflagration”, an elaboration of ᴱQ. pur (purn-) “a fire” with an (optional) prefix of ᴱQ. uru “fire” (QL/75), so perhaps “*(lit.) fiery fireness”.

Neo-Quenya: For purposes of Neo-Quenya, I’d use ruive for a basic “wild fire”, and augmented aparuivë for a massive conflagration.