A variant of talan (talam-) “flat space, platform” in notes on Words, Phrases and Passages from the Lord of the Rings (PE17/52).
Neo-Quenya: I would not use this word for this purpose in Neo-Quenya, since elsewhere talma was used for “basis, base, foundation, root” (PE21/80; Ety/TAL).
talma noun "base, foundation, root" (TALAM), also translated "bottom" in the expression "top to bottom", see below.% Talmar Ambaren (place-name, *"Foundations of the World" - this is pre-classical "Qenya" with genitive in -en instead of -o as in LotR-style Quenya) (TALAM). Allative talmanna in the phrase telmello talmanna** "from hood to base**, top to bottom" _(VT46:18; notice misreading "telmanna" in the Etymologies as printed in LR, entry TEL-, TELU-)_