This and similar roots were connected to Elvish words for maidenhood for much of Tolkien’s life. The earliest form of this root was unglossed {ᴱ√WENE >>} ᴱ√GWENE in the Qenya Lexicon of the 1910s with derivatives like ᴱQ. ’wendi “maiden” and ᴱQ. ’wendele “maidenhood” (QL/103). In the contemporaneous Gnomish Lexicon the primitive form was given as {ᴱ✶gw̯ene >>} ᴱ✶gu̯eđe having derivatives like G. gwennin “girl” and {G. gwendi >>} G. gwethli “maiden, little girl” (GL/45).
In The Etymologies of the 1930s Tolkien gave the root as ᴹ√WEN “maiden” with extension ᴹ√WENED and derivatives like ᴹQ. venesse/N. gweneth “virginity” and ᴹQ. vende/N. gwenn “maiden” (Ety/WEN). In this entry Tolkien later wrote “transfer to GWEN”, indicating a relationship to ᴹ√GWEN, a root in The Etymologies with derivatives having to do with youth and freshness (Ety/GWEN). The root √WEN mostly retained the sense “maiden” in Tolkien’s later writings, though occasionally Tolkien said it was originally a more general feminine root before developing the more limit sense “young woman” (PE23/87; VT48/18).
The root √WEN(ED) appeared a number of times in Tolkien’s later writings, mostly as the basis for Q. wendë/S. gwen(d) “maiden” (PE17/191; VT47/17; VT48/18). The frequency with which Tolkien used Q. wendë over Q. vendë indicates the primitive root may have been strengthened to ✱√GWEN(ED), since w derived from primitive gw survived longer in Quenya than ancient primitive w; see the entry on Q. vendë for further discussion.
A noun translated “girl” and fully declined as an example of a feminine Strong I noun (SD/430). It is also used as an example of feminine nouns that use the suffix -i in their objective inflection as opposed to the usual -u: nithli (SD/431). Though not explicitly stated, nithli is also an example of the variant objective-with-syncope syntax discussed on SD/435. Carl Hostetter and Patrick Wynne suggested (AAD/21) it may be related to the Elvish root √NETH “young”.