The name Túrin gave to his sister Nienor when she had lost her memory and he didn’t recognize her, translated “Tear-maiden” (S/219), a combination of nîn “tear” and the feminine suffix -iel.
Conceptual Development: She was called G. Níniel “Child of Tears” in the earliest Lost Tales (LT2/112), and in Silmarillion drafts from the 1930s, the name N. Níniel was translated “Tearful” or “Tear-maiden” (SM/129, 306; LR/140).
nîn (“tear”) + iell (“daughter” [Etym.] SEL-Dtraditional ending for women’s names)