Noldorin 

dolen

noun. concealed, hidden

Noldorin [Ety/355] Group: SINDICT. Published by

dolen

adjective. hidden, secret

muin

adjective. secret

Noldorin [EtyAC/MUY] Group: Eldamo. Published by

thurin

adjective. secret, hidden

Noldorin [LB/304, Ety/394] Group: SINDICT. Published by