ADRIATIC

      - From Latin Adriaticus, (Hadriaticus) after the ancient city Atria/ Hatria (modern Adria),

near Venice† | Italy. Perhaps from atra, (neuter of atrum) = black, hence "the black city;"

or else Illyrian adur = water, sea🔍 [PIE🔍 root wódr̥ = water (also source of Greek hydro)]

† Once a seaport but now 12+ miles inland