S. côf n. “bay” (Category: Gulf, Bay)
The earliest iteration of this word seems to be G. gobos “haven” in the Gnomish Lexicon of the 1910s, cognate to ᴱQ. kôpa(s) (GL/40). In Early Noldorin Word-lists of the 1920s, Tolkien had ᴱN. cû “bay, cove”, again as a cognate of ᴱQ. kópa (PE13/141). In The Etymologies of the 1930s it was N. hûb “haven, harbour, small landlocked bay” derived from the root ᴹ√KHOP (Ety/KHOP). In notes on The Rivers and Beacon-hills of Gondor from the late 1960s, Tolkien use S. côf “bay” in a pair of names: S. Côf Belfalas “Bay of Belfalas” and S. Côf Gwaeren Bel “Windy Bay of Bel”, but the section where it appeared was rejected (VT42/15).
Neo-Sindarin: For purposes of Neo-Sindarin, I’d use the 1930s form hûb for “bay”, because (a) it is the latest form that was not rejected and (b) is compatible with an attested Quenya form ᴹQ. hópa of the same meaning.
Reference ✧ VT42/15 ✧ Côf “bay”
Reference ✧ Ety/KHOP ✧ “haven, harbour, small landlocked bay”
|ᴹ√KHOP > hûb||[kʰōpa] > [kʰūpa] > [xūpa] > [xūp] > [xūb] > [hūb]||✧ Ety/KHOP|