Dau Family History
Dau Surname Meaning
North German East Frisian and North Frisian: from the Frisian personal name Douwe from dou ‘pigeon’.
South German: from Davo a short form of the personal name Tavold formed with Old High German dau ‘custom tradition’.
Vietnamese (Đậu): from the Chinese surname 竇 see Dou.
Source: Dictionary of American Family Names 2nd edition, 2022