Primitive elvish
ṃbar
noun. ṃbar
mbar
root. settle, dwell; establish, fix, decide, determine, make a decision, settle; establish, fix, decide, determine, make a decision; dwell, [ᴹ√] inhabit, [ᴱ√] live
mēlā̆-mbar
noun. beloved dwelling
mbar-
verb. to dwell
ambar(a)
noun. the settlement, establishment, the world
hekla-mbar
place name. Eglamar
tura-mbar
masculine name. master of fate
mbar(ă)
noun. dwelling, habitation
keme
noun. earth
kemen
noun. earth
ṃbart(ă)
noun. fate, doom; (orig.) permanent establishment
This root was connected to the sense “dwell” for all of Tolkien’s life. In the Qenya Lexicon of the 1910s it appeared as ᴱ√MBARA “dwell, live”, though in Qenya it was blended with ᴱ√ŊWAÐA “tarry, linger” since [[eq|initial [ŋʷ] became [m]]] (QL/60). In Gnomish the two roots remained distinct: G. bar “home” (GL/21) vs. G. gwadh- “dwell” (GL/46). However, other Gnomish derivatives hint at an unstrengthened variant ᴱ√MARA: G. mar “Earth, ground, soil” and G. Môr “The Earth”, of which Tolkien said “mar and môr probably conceal two roots and a confusion; mbara” (GL/56). The source of this confusion might be ᴱ√MARA “ripe” (QL/59, 63).
In The Etymologies of the 1930s the root appeared as ᴹ√MBAR “dwell, inhabit” (Ety/MBAR); an earlier version of this entry had the extra gloss “build” (EtyAC/MBAR). In The Etymologies, it seems this root was a strengthened form of ᴹ√BAR “raise” (Ety/BAR), but the root ᴹ√MBARAT “fate” seems to be unrelated at this point (Ety/MBARAT). The root mbar- was mentioned in the Outline of Phonetic Development (OP1) from the 1940s (PE19/36) and again as √MBAR “{house >>} dwell” in the second version of Tengwesta Qenderinwa (TQ2) from around 1950 (PE18/92).
The root √MBAR still had the basic sense “dwell” in Notes on Galadriel’s Song (NGS) from the late 1950s or early 1960s (PE17/64); in those notes it seems it was distinct from both √BAR “raise” and √MAR(AT) or √MBART “doom, fate” (PE17/66). But in notes on Fate from 1968 (NM/226-231; PE17/104-109), Tolkien shifted the meaning of the root:
> English “settle” in its various branches of meaning closely resembles the development of the meanings of √MBAR: thus settlement can mean the act of colonizing or taking up an abode, or the area or place so occupied (by a family or community); or (the terms of) an agreement fixed after debate. The development was not, however, the same: the senses of settle proceed from a sense “place in or take up” a firm position, especially in a place that seems suitable; from which the sense of settling affairs that were in confusion or doubt arose. √MBAR meant basically to make a decision, and the meanings relating to dwelling or occupying land proceeded from that (PE17/105).
This new definition for √MBAR was to support a more direct connection between this root and words like Q. umbar “fate”, hence establishing an etymological relationship to extended √MBARAT for the first time, for example with √MBAR > ✶mbartā- “to define, decree, destine” (PE17/104).
Neo-Eldarin: For purposes of Neo-Eldarin, I think this late 1960s meaning “settle, decide, establish; (by extension) dwell” is probably the best.