ambo noun "hill, rising ground" (Markirya, PE17:92), "mount" (PE17:157), allative pl. ambonnar "upon hills" in Markirya (ruxal' ambonnar "upon crumbling hills") According to VT45:5, ambo was added to the Etymologies as a marginal note.
Quenya
ambo
noun. hill, rising ground, mount
ambo
hill, rising ground
ambos
breast
ambos (ambost-) noun "breast" (chest). PE16:82
ambona
noun. hill
umbo
hill, lump, clump, mass
umbo, umbon noun "hill, lump, clump, mass" (PE17:93)
amboremma
noun. bust, (lit.) breast-picture
@@@ Discord 2023-01-11, cf. Finnish rintakuva
ambos
noun. breast, *chest
amun
hill
amun (amund-) noun "hill" (LT2:335; in Tolkien's later Quenya ambo)
oro
mount, mountain
oro (1) noun "mount, mountain" (PE17:64), cf. Qenya oro noun "hill" (LT1:256; rather ambo in LotR-style Quenya, though #oro "mountain, hill" appears in Orocarni and orofarnë, q.v. [PE17:83], also with the meaning "high" in oromar, q.v.) Cf. oro- element "up, aloft" (PE17:64).
ambar
breast
ambar (3) noun ""breast" (chest), with stem in -s- or -r- (QL:30). The form ambar, translated "in bosom", occurs in MC:213 (this is "Qenya"). Note: if this word were to be adapted to LotR-style Quenya, we should probably have to read *ambas with stem ambar-; compare olos, olor- "dream" from a late source. However, the form ambos (q.v.) is less ambiguous and may be preferred.
Túna
hill, mound
Túna (also Tún) place-name, used of the hill on which Tirion was built (Silm, TUN, KOR), derived from a stem (TUN) apparently meaning simply *"hill, mound".
amban
upward slope, hill-side
amban noun "upward slope, hill-side" (AM2)
ampendë
upward slope
ampendë noun "upward slope" (PEN/PÉNED)
tundo
hill, mound
tundo noun "hill, mound" (TUN)
The basis word for “hill” in Quenya (MC/222; PE17/90), also referring to “rising ground” in general (PE17/92).
Conceptual Development: The earliest precursor of this word was ᴱQ. †amun (amund-) “hill” in the Qenya Lexicon of the 1910s, a derivative of ᴱ√AM(U) “up(wards)”, though this word was marked as poetic (QL/30); amund- “hill” was also mentioned in the Poetic and Mythological Words of Eldarissa (PME/30). The form ᴱQ. ambo “hill” first appeared in Early Noldorin Word-lists of the 1920s as a cognate of ᴱN. amon (PE13/137, 159), and it (mostly) retained this form thereafter.
ᴹQ. ambo “hill” reappeared in The Etymologies of the 1930s as a derivative of ᴹ√AM “up” (Ety/AM²). In notes on the comparative from early in 1967, Tolkien coined some different roots as the basis for this word, first √MAB “lump, mass” (PE17/90) and then √MBON, the latter producing Q. umbo(n) “hill, lump, clump, mass” (PE17/90-93), his motivation being that he wanted √AMA to have a new meaning “addition, increase, plus” to serve as the basis for the intensive. But in other notes from 1967 he derived Q. ambo from √AM “go up”, though in that note he glossed the word as “mount” (PE17/157). In the Q. Markirya poem from late 1960s, ambo was used for “hill” (MC/222).
Neo-Quenya: For purposes of Neo-Quenya, I would assume Q. ambo was derived from √AM “up”, and would limit its used to hills, ignoring its 1967 “mount” gloss.