luimë noun "flood" (VT48:23, 30; the additional glosses "floodwater, flooded land" were struck out, VT48:30), "flood, high tide" (VT48:24, 30). According to VT48:30, partially illegible glosses in Tolkien's manuscript may also suggest that luimë can be used for any tide, or for the spring tide (the maximum tide just after a new or full moon).
Quenya
luimë
noun. flood, floodwater, flooded land; flood tide, high tide, flood, floodwater; flood tide, high tide; flooded land
luimë
flood
lúto
flood
lúto noun "flood" (LT1:249)
ulundë
flood
ulundë noun "flood" (ULU), possibly in the sense of (great) river.% Cf. nuinë, oloirë.
A noun glossed {“flood, floodwater, flooded land”} (VT48/23) >> “flood, flood tide, high tide, [?or any] tide” (VT48/30 note #3) or “flood, high tide” (VT48/24), based on the root √DUY and appearing in notes on Variation D/L in Common Eldarin from the late 1960s.
Conceptual Development: The Qenya Lexicon and Poetic and Mythological Words of Eldarissa of the 1910s had ᴱQ. lūto “flood” based on the early root ᴱ√LUTU (QL/57; PME/57). The Etymologies of the 1930s had ᴹQ. ulunde “flood” under the root ᴹ√ULU “pour, flow” (Ety/ULU). See also oloirë “great flood” (VT42/10), likewise from the late 1960s.
Neo-Quenya: For purposes of Neo-Quenya I would interpret luime to mean to a state of elevated water from any source, either a river flood or a high tide. For a more disastrous “great flood” I would use oloirë. I would using ᴹQ. ulunde for a “flood” pouring from above such as heavy rain, hence also “✱downpour”.