This root first appeared in The Etymologies of the 1930s as ᴹ√NIS “woman”, an extension of ᴹ√NĪ “female” (Ety/NIS). It also had a strengthened form ᴹ√NDIS, unglossed but apparently meaning “bride” based on its derivatives ᴹQ. indis/N. dîs of that meaning (Ety/NDIS). Unstrengthened ᴹ√NIS seems to have survived only in Quenya as the basis for ᴹQ. nis (niss-) “woman”, but this word was also blended with ✱ndis-sē to produce a longer form nisse of the same meaning.
In Tolkien’s later writings, both short Q. nís and longer nissë appeared as words for “woman” (MR/213; VT47/33) and Q. indis reappeared as well, though glossed “wife” (UT/8). As primitive forms, both unstrengthened √nis (VT47/33) and strengthened ✶ndī̆s “woman” also appeared in later writings, the latter given as the feminine equivalent of ✶[[p|n[d]ēr]] “man” (PE19/102).
This root was connected to words for “many” throughout Tolkien’s life. In the Qenya Lexicon of the 1910s it appeared as ᴱ√LĪ, with variant ᴱ√ILI “many” and extended form ᴱ√LIYA (LI + ya) “unite many as one” with derivatives like ᴱQ. lia- “entwine” and ᴱQ. liante “tendril” (QL/42, 53). In later writings there is no sign of the inversion √IL “many” (later √IL meant “all”), whereas ᴱ√LIYA seems to have shifted to unrelated ᴹ√SLIG with derivatives like ᴹQ. lia “fine thread, spider filament” and ᴹQ. liante “spider” (Ety/SLIG).
The base root ᴹ√LI “many” did reappear in The Etymologies of the 1930s, however (Ety/LI), and √LI “many” appeared again in etymological notes from the late 1960s (VT48/25). The long-standing connection between this root and the Quenya (partitive) plural suffixes indicates its stability in Tolkien’s mind.