(fem.) #oneth pl. *onith. Isolated from the following:
Sindarin
oneth
noun. *giver [f.]
oneth
noun. giver
oneth
giver
oneth
giver
pl. ✱onith. Isolated from the following:
besain
noun. the Lady, breadgiver
In notes from the 1950s Tolkien said the word besain was a title for noble Elf ladies as the provider of lembas, the equivalent of (and probably adapted from) Q. massánië, literally “bread giver [giving]” (PM/404). It was likely coined based on the historical developments of this name: ✱mbassānye > (m)bessenı̯ > bessein > besain. Christopher Tolkien noted that his father wrote oneth above -ain, indicating an alternate form, which Christopher Tolkien wrote as ✱besoneth (PM/405). However, I think it is likelier the alternate would be ✱basoneth = S. bas “bread” + oneth “✱giver [f.]”, because in this alternate form there would be no reason for the initial element bas- to undergo i-affection.
An unglossed word element given in 1950s notes Tolkien gave as part of an incomplete alternative to besain “bread giver” (PM/404), probably ✱[bas]oneth. Thus oneth is probably a feminine word for “giver”.