Qenya
aryon
noun. heir
haryon
noun. prince (heir)
hilde
noun. heir
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!
Two similar words appeared in The Etymologies of the 1930s: ᴹQ. aryon “heir” as a derivative of the root ᴹ√GAR, and ᴹQ. haryon “(heir) prince” as a derivative of the root ᴹ√ƷAR, both roots having to do with possession (Ety/GAR; Ety/ƷAR). Drafts of these entries had aryo, aryon “son of property = heir” and aryon “heir, prince” (EtyAC/GAR; EtyAC/ƷAR). Based on the gloss “son of property”, I think it is likely the second element of these words is the root ᴹ√YO(N) “son”.
Neo-Quenya: It is possible Tolkien intended haryon and aryon to coexist, but since we have other “prince” words I would just use aryon “heir = one who inherits wealth” for purposes of Neo-Quenya.