Early Noldorin
gwib
noun. teors, *penis
gwî Archaic
noun. teors, *penis
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
A noun ᴱN. gwib “teors” (Old English = “penis”) appeared in Early Noldorin Word-lists of the 1920s derived from ᴱ✶wiqē, along with an archaic variant ᴱN. †gwî of the same meaning from primitive ᴱ✶wiı̯ḗ (PE13/146, 162).
Neo-Sindarin: I’d adapt these words as ᴺS. gwîb “penis” for purposes of Neo-Sindarin with long î, derived from ✱wēkwē based on a variant of the root ᴹ√WEG having to do with vigour.