ᴺS. [G.] ^sunt n. “nostrils” (Category: Nose)
The noun G. hunt “nostrils, nose, snout” appeared in the Gnomish Lexicon of the 1910s, where Tolkien said it was “properly [an] old dual” (GL/50). In The Gnomish Grammar Tolkien gave it the gloss “the nose (originally nostrils)”, and specified that it was based on an old dual suffix -nt. It may have been derived from some variant of the early root ᴱ√SUHYU “breath, exhale, puff”, and may be related to ᴱQ. súma “nostril” (QL/86).
Neo-Sindarin: For purposes of Neo-Sindarin, I would adapt this as ᴺS. sunt “(pair of) nostrils” from the later root √SŪ “blow” as a now-obscure fossilized dual of *sūm(ă) (?“blow-thing”) combined with the ancient dual suffix ✶-t, where sūm-t(ă) > sunt. A single nostril would be sunneg with the singular suffix -eg. Sindarin has a similar fossilized dual form: lhaw “(pair of) ears” vs. lheweg “ear”.
References ✧ GG/10; GL/50