Where does “ϩⲁⲗⲁⲥⲥⲁ” come from?

ϩⲁⲗⲁⲥⲥⲁ (Coptic) comes from Coptic ⲑⲁⲗⲁⲥⲥⲁ, from Ancient Greek θάλασσα — sea; the Mediterranean Sea; channel.

ϩⲁⲗⲁⲥⲥⲁ (Coptic): Alternative form of ⲑⲁⲗⲁⲥⲥⲁ