The name Barossa means Muddy and is of Spanish origin. Barossa is name that's been used by parents who are considering unisex or non-gendered baby names--baby names that can be used for any gender.
Spanish and Portuguese words for muddy.
The Barrosa mountain range in western Australia was named by Colonel William Light in 1837 after Barrosa Hill (Cerro de Puerco) in the modern municipality of Chiclana de la Frontera, Spain, to which it he thought it similar. The Spanish location was the site of the Battle of Barrosa and was won by Light's friend Lord Lynedoch in 1811.