A word for “womb” in Quenya prayers of the 1950s; the editors of the prayers suggested it is probably connected to √MŌ “labour” (VT43/31).
Conceptual Development: Earlier versions of the prayers had carva instead, possibly connected to √KAR “make” (VT43/31). In notes on Elvish growth from 1959, Tolkien had two different words for “gestation”: colbamarië (NM/91) and colbanavië (NM/120). The initial elements of these might be colba “✱womb”, with meanings “✱womb-dwelling” and “✱womb-being” respectively.
Neo-Quenya: Giving the tentative nature of the interpretations of colba, I’d stick with móna for “womb” for purposes of Neo-Quenya.
A noun for “gestation” in notes on Elvish life cycles from 1959, appearing in the form colbamarië and colbanavië (NM/91, 120). The initial element is colba in both cases, which might mean “womb” based on the root √KOL “bear, carry”. The final elements are marië (perhaps = “dwelling”) and navië (probably = “being”), so the literal meanings may be “✱womb-dwelling” and “✱womb-being”.