Blau Family History
Blau Surname Meaning
German: from Middle High German blā ‘blue’ (Old High German blāo) applied as a nickname with various senses: someone who habitually wore blue clothes, a dyer, someone with blue eyes, a sickly or pale person, someone with a bluish complexion resulting from poor circulation, etc.
Jewish (Ashkenazic): artificial name from German blau ‘blue’ (see 1 above). In some cases possibly also Catalan: nickname from blau ‘blue’.
Source: Dictionary of American Family Names 2nd edition, 2022
