Q. lís (liss-) n. “honey” (Category: Honey)
A word for “honey” in Definitive Linguistic Notes (DLN) from 1959 given as lîs and derived from the root √(G)LIS (PE17/154); the usual representation of a long vowel in Quenya would be *lís. In DLN Tolkien said that it sometimes appeared as līr- in inflections with the usual change of intervocalic s to r, but that its usual stem form was liss-. Indeed, in The Etymologies of the 1930s this word was ᴹQ. lis “honey” under the root ᴹ√LIS of the same meaning, and its stem form was also liss- as indicated by its [ᴹQ.] genitive lissen (Ety/LIS). Tolkien originally gave the base noun as lisse in The Etymologies, but this was deleted and replaced by lis (EtyAC/LIS). In The Etymologies its Noldorin cognate was N. glî.
Neo-Quenya: Since there are other honey-words in Quenya like Q. nehtë, I would use lís (liss-) for sweeteners in general, including both honey and sugar.
References ✧ PE17/154
|liss-||stem||✧ PE17/154: oblique līr- but usually from stem liss-|
|√(G)LIS > lîs||[līs]||✧ PE17/154|
References ✧ Ety/LIS; EtyAC/LIS
|ᴹ√LIS > lis||[liss] > [lis]||✧ Ety/LIS|