The seventh line of the Markirya poem (MC/222). The first word is wilwarin “butterfly” modified by the adjective wilwa “fluttering to and fro”, which is more loosely translated as “vague” in the poem itself. The English preposition “as” is not reflected in the Quenya text, and may be an artifact of the Early Qenya version of the poem.
Decomposition: Broken into its constituent elements, this phrase would be:
> wilwarin wilwa = “✱butterfly fluttering”
wilwa adj. "vague, fluttering to and fro" (_Markirya). _A similar word in the Etymologies was struck out: [wilwa > vilwa] "air, lower air" (distinct from the 'upper' air of the stars, or the 'outer') (WIL) According to VT46:21, Tolkien considered wilda > vilda as a replacement form, but rejected it.