An adjective for “deep” in The Etymologies of the 1930s derived from ᴹ✶nūrā under the root ᴹ√NUR of the same meaning (Ety/NUR).
Noldorin
tofn
adjective. lowlying, deep, low
tofn
adjective. lowlying, deep, low
nûr
adjective. deep
nûr
adjective. deep
An adjective appearing as N. tofn “lowlying, deep, low” in The Etymologies of the 1930s, derived from ᴹ✶tubnā “deep” under the root ᴹ√TUB (Ety/TUB).
Neo-Sindarin: For purposes of Neo-Sindarin, I would adapt this word as ᴺS. tovn “lowlying, deep, low” to better fit Sindarin orthography.