A Quenya noun for “lily” or more generally any “large flower”, cognate of Ad. inzil.
Conceptual Development: This word appeared in two forms with competing etymologies. In the early 1950s, it appeared as Q. insil, a loan word from Atani inzil, where the [[aq|[nz] became [ns]]] (PE19/99). A similar word indil appeared in the 1959-60 essay Quendi and Eldar, where it was a derivative of Valarin iniðil (WJ/399), with the middle i lost due to the Quenya syncope and then the [[q|spirant [ð] becoming the stop [d] after the nasal [n]]].
In the second scenario, Tolkien did not directly connect Q. indil to Ad. inzil, but the coincidence of forms is too great: Tolkien must have imagined a reverse loan from Valarin > Quenya > Atani. Perhaps this loan took place before the [ð] became [d] in Quenya ([[q|[nð] > [nd]]]), and the voiced spirant was adapted as the sibilant [z] in Atani because that language did not possess spirants in its earliest historical stages.
I personally prefer this second scenario and the form indil, because using the first scenario would require discarding one of our few Valarin words (iniðil).
indil noun "lily", or other large single flower. Adopted and adapted from Valarin. (WJ:399)