A word for “heir” appearing only in its possessed plural form hildinyar in the phrase sinomë maruvan ar Hildinyar tenn’ Ambar-metta “In this place will I abide, and my heirs, unto the ending of the world” (LotR/967). It had this same form in its first appearance in Lord of the Rings drafts of the 1940s (SD/56), and is clearly based on the root √KHIL “follow” (PE17/18; WJ/387; Ety/KHIL). It is very similar to Hildor “Men, Aftercomers, (lit.) Followers” (S/99; WJ/219, 386), which sometimes appeared as Hildi instead, especially in earlier writings (MR/130; PE17/18, 101; Ety/KHIL). Its singular form is generally assumed to be hilde, probably with stem form hildi-, but it could be hil (hild-) instead.
Conceptual Development: The Qenya Lexicon of the 1910s had ᴱQ. hil or ᴱQ. hilde “child” under the early root ᴱ√HIL [χili] (QL/40), also mentioned in the Poetic and Mythological Words of Eldarissa (PME/40). In the contemporaneous Gnomish Lexicon it was derived from primitive ᴱ✶χilþē and equated to G. hiltha “youth of either sex, more often masc” (GL/49). The sense “child” seems to have been later tranfered to hína.
Neo-Quenya: For purposes of Neo-Quenya, I would would assume the basic meaning of hilde is “one who comes after me”, and thus is applicable to both descendents or followers. For “heir = one who inherits my wealth” I would instead use [ᴹQ.] aryon. I would further assume hilde is generic, and distinct from Hildo “Man = After-comer”.
hildi, -hildi noun "followers" (used = mortal men, the Second-born of Ilúvatar) (KHIL) (also Hildor, q.v.). Dat. pl. hildin "for men", a dative pl. occurring in Fíriel's Song. Cf. hildinyar "my heirs", evidently *hildë, hildo "follower, heir" + -inya "my" + -r plural ending (EO)