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!
nesse
noun. (green) fodder, herb, grass
nessele
noun. pasture, mead; pasturage
The noun ᴱQ. nessele appeared in the Qenya Lexicon of the 1910s with the gloss “pasture, mead; also = pasturage”, a derivative of the early root ᴱ√NESE “give to feed; feed, pasture; graze” (QL/66). It was also mentioned in the Poetic and Mythological Words of Eldarissa with the gloss “pasture” (PME/66).
Neo-Quenya: I would retain this word as ᴺQ. nesselë “pasture, mead[ow]; pasturage” for purposes of Neo-Quenya, derived from the Neo-Root ᴺ√NES.
nesta-
verb. to feed
The verb ᴱQ. nesta- “feed” appeared in the Qenya Lexicon of the 1910s as a derivative of the early root ᴱ√NESE “give to feed; feed, pasture; graze” (QL/66). It has past forms nēse and nesse, indicating a close relationship to the verb ᴱQ. nese- “graze, pasture, give to feed, feed” from the same root, which likely would have had the same or similar past-tense forms.
Neo-Quenya: For purposes of Neo-Quenya, I would combine both these early verbs into ᴺQ. nesta- “to graze, pasture, give to feed, feed”, derived from the Neo-Root ᴺ√NES.
A noun in the Qenya Lexicon of the 1910s glossed “(green) fodder, herb, grass” under the early root ᴱ√NESE (QL/66). In the contemporaneous Poetic and Mythological Words of Eldarissa it was glossed “green fodder” (PME/66).