Where does “Deniz” come from?

Deniz (Turkish) comes from Ottoman Turkish دكز, from Proto-Turkic teŋiŕ, from Old Turkic teŋ, from Middle Chinese 等.

Ancestry of “Deniz”, step by step

Step	Language	Word	Meaning
1	Ottoman Turkish	دكز	sea
2	Proto-Turkic	teŋiŕ	sea
3	Old Turkic	teŋ	equivalent, balanced; equal, equivalent,...
4	Middle Chinese	等	—

Deniz — Etymology, Origin & Word History | Etymology Explorer