furin adj. "hidden, concealed" (also hurin, which form may be preferred in a LotR-compatible form of Quenya) (LT2:340)
Quenya
undu
down
foina
hidden
furin
hidden, concealed
hurin
hidden, concealed
hurin adj. "hidden, concealed" (also furin) (LT2:340)
undu
down, under, beneath
undu adv. (and prep.?) "down, under, beneath" (UNU, VT46:20); prefixundu- "down", in undulávë "down-licked" = covered. (Nam)
muina
hidden, secret
muina adj. "hidden, secret" (MUY)
foina adj. "hidden" (LT2:340)