1) (a single hair) fîn (construct fin), no distinct pl. form. (PM:362), 2) (lock of hair, tress) find (construct fin), no distinct pl. form, coll. pl. finnath.
Sindarin
fîn
noun. (single) hair, filament
fîn
noun. a tress
find
noun. a tress
finn-
noun. a tress
fîn
hair
fîn
hair
(construct fin), no distinct pl. form. (PM:362)
find
hair
(construct fin), no distinct pl. form, coll. pl. finnath.
find
tress
find (lock of hair). Construct fin; no distinct pl. form; coll pl. finnath.
find
tress
(lock of hair). Construct fin; no distinct pl. form; coll pl. finnath.
cidinn
?. [unglossed]
cinnog
?. [unglossed]
laws
noun. hair ringlet
madu
?. [unglossed]
maud
?. [unglossed]
fast
shaggy hair
(pl. faist if there is a pl.).
A noun for a single hair appearing in The Shibboleth of Fëanor from 1968 derived from primitive ✶phini- (PM/362 note #37). The form fin- also appeared in a torn-half sheet as a derivative of √SPIN- “a single hair, filament” (PE17/17).
Conceptual Development: Earlier words for a single hair include G. fith, pl. fidhin from the Gnomish Lexicon of the 1910s (GL/35) and ᴱN. fîr from Early Noldorin Word-lists of the 1920s (PE13/143).