iaur (“ancient, old”) + sael (“wise”)
Sindarin
iorhael
masculine name. Frodo
Iorhael
noun. old-wise (Frodo)
Iorhael
Iorhael
The meaning is "old-wise" and comes from iaur and sael.
daur
masculine name. Frodo
A Sindarin name for Frodo, used in the Praises of Cormallen (LotR/953, Let/448). It apparently means “wise” (Tolkien’s gloss is unclear), a derivative from Primitive Elvish ✶dāra (PE17/102). Compare this to Iorhael, a Sindarin translation of the name of Sam’s son Frodo, used in the King’s Letter.
A Sindarin translation of the name of Sam’s son Frodo appearing in Tolkien’s unpublished epilogue to The Lord of the Rings and in the King’s Letter (SD/126, 129), distinct from Frodo Baggin’s Sindarin name: Daur. The name of Sam’s son appears to be a combination of the prefixal form ior- of iaur “old” and the lenited form of sael “wise”, also seen in the Sindarin translation of the name Samwise (Halfwise): Perhael.
Conceptual Development: In earlier versions of the epilogue the name appeared as N. Iorhail (SD/117), which seems to contain an earlier word N. sail “wise” based on Noldorin phonology: see N. [[n|[ai] revised to [ae]]].