Beware, older languages below! The languages below were invented during Tolkien's earlier period and should be used with caution. Remember to never, ever mix words from different languages!
hen
noun. eye
hendor
masculine name. Hendor
hent
noun. eyesight
uil
noun. hen
porogwil
noun. hen
The word G. porogwil appeared in the Gnomish Lexicon of the 1910s as a combination of G. porog “fowl (domestic)” and G. uil “hen” (GL/64, 74).
Neo-Sindarin: I would adapt this word as ᴺS. porochuil for purposes of Neo-Sindarin, updating the second element to the neologism ᴺS. huil “hen”. The longer form is better distinguished from ᴺS. huil “bitch, female dog”.
haiva
interjection. hence!, begone, be off; (as av.) away, hence, off
hai
interjection. go!, hence, begone, away
fenog
adjective. venomous
A word appearing as G. fenog or {fembrin >>} fenwed “venomous” in the Gnomish Lexicon of the 1910s, an adjectival form of G. fem “venom (of snakes), poison in general” (GL/34).
Neo-Sindarin: For purposes of Neo-Sindarin, I would update this word to ᴺS. lhoereb “venomous, poisonous” based on the later word lhoer “venom, poison(ousness)”.
aigli
noun. bird
beb
adverb. [unglossed]
bil
noun. bird
A word for “bird” in the Gnomish Lexicon of the 1910s appearing next to G. bilinc “sparrow”, but this word was deleted and the gloss for bilinc was expanded to “a small bird, especially sparrow” (GL/22-23). The form bil appeared in a couple other places in the Gnomish Lexicon (GL/23, 31), but seems to represent a “root” rather than a word. Tolkien indicated bil was derived from ᴱ✶du̯il (GL/31), but the exact mechanism whereby du̯- became b- isn’t clear, but a similar change is seen in 1920s ᴱ✶du̯ag- > ᴱT. baga- “beat” and ᴱ✶tu̯ak- > ᴱQ. pak- “apply, attach” (PE14/66).
brid-
verb. [unglossed]
clidhron
noun. [unglossed]
climbol
noun. [unglossed]
crisc
adjective. sharp
dôn
?. [unglossed]
fenwed
adjective. venomous
fî
noun. [unglossed]
gatha
?. [unglossed]
@@@ form does not appear elsewhere and similar forms are not relevant
hethos
noun. brother
pad
noun. [unglossed]
praust
noun. [unglossed]
prog
noun. [unglossed]
rab-
verb. [unglossed]
rô
noun. [unglossed]
segrin
adjective. middle
sind
noun. [unglossed]
sinthi
pronoun. [unglossed]
sitha
adjective. this
thail
noun. [unglossed]
thel
noun. [unglossed]
thelg
noun. [unglossed]
thil
noun. [unglossed]
thion
noun. [unglossed]
thrim
?. [unglossed]
thû-
verb. [unglossed]
trum
?. [unglossed]
tûn
noun. [unglossed]
ulthanc
noun. [unglossed]
umeg
?. [unglossed]
’ôs
noun. [unglossed]
The word G. uil “hen” appeared in the Gnomish Lexicon of the 1910s (GL/74), almost certainly a cognate of ᴱQ. oi “bird, hen” which Tolkien considered deriving from ᴱ√OHO “cry” (QL/69). In Common Eldarin: Noun Structure from the early 1950s, Tolkien had the primitive word ✶kholjē “hen” derived from the root √KHOL “crow, cry aloud” (PE21/82), which may be a later iteration of this Gnomish uil “hen” word.
Neo-Sindarin: Based on the above, Gábor Lőrinczi proposed a neologism ᴺS. hŷl “hen” as recorded in the VQP (VQP). However, my analysis of Sindarin phonology indicates that ᴺS. huil is the more likely result ✶kholjē: compare thuil and thuin plurals of thôn and thôl, and possibly also ruin < ✱runyā and fuir < ✱forya. For further details see the entry on how [[s|final [i] intruded into preceding syllable]] in Sindarin.
In any case, I recommend ᴺS. huil for “hen” in Neo-Sindarin, or its more elaborate form ᴺS. porochuil.