A noun appearing only it is plural form fui “paths” in the name Fui ’Ngorthrim “Paths of the Dead” (RC/526). The most plausible singular form is ✱fû “path”.
Noldorin
lhonn
noun. (narrow) path, strait, pass
lhonn
noun. narrow path or strait
lhonn
noun. entrance to harbour, land-locked haven
lonn
noun. narrow path or strait
lonn
noun. entrance to harbour, land-locked haven
lonn
noun. path
hûn
noun. heart (physical)
lond
noun. narrow path or strait
lond
noun. entrance to harbour, land-locked haven
râd
noun. path, track
(i vâd, construct bad) (beaten track), pl. baid (i maid).