A word appearing as ᴱQ. larúva “greasy”, an adjectival form of ᴱQ. laru “fat, grease” in the Qenya Lexicon of the 1910s under the early root ᴱ√LARA (QL/51). In Early Qenya Word-lists of the 1920s Tolkien instead had ᴱQ. lisiva “greasy” as the adjectival form of ᴱQ. lise (lisy-) “grease” (PE16/141).
Neo-Quenya: The root ᴹ√LAR “fat, grease” from The Etymologies of the 1930s seems to indicate that lisy- was a transient idea, so I would retain ᴺQ. larúva “greasy” for purposes of Neo-Quenya. Note that Tolkien also had a different adjective Q. (h)lúvo “greasy, fat” in notes from the early 1950s (PE21/82), but I think the two can coexist.
A word appearing as ᴱQ. laru “fat, grease” in the Qenya Lexicon of the 1910s under the early root ᴱ√LARA whose derivatives had to do with fat (QL/51). In Early Qenya Word-lists of the 1920s Tolkien instead had ᴱQ. lise {“greasy” >>} “grease”, with an accusative form lisya- indicating a stem lisy- (PE16/141). In Qenya Declensions also from the 1920s, its partitive form lisihta was glossed “of butter” (PE16/115).
Neo-Quenya: The root ᴹ√LAR “fat, grease” from The Etymologies of the 1930s seems to indicate that lisy- was a transient idea, so I would retain ᴺQ. laru for purposes of Neo-Quenya, but would use it only for “grease”. For “fat” I would instead use ᴹQ. larma (Ety/LAR). Note that Tolkien also had the adjective Q. (h)lúvo “greasy, fat” in notes from the early 1950s (PE21/82) but gave no noun form.