Ustarri (-)
(with) definite article: UstarriaName in Gipuzkoa; NB¹: ➺ Busterri, and Buztarri; NB²: Similar terms, also encountered in Gipuzkoa (➺ Uztarri [the only spelling encountered as an entry in dictionaries!], and Uzterri) seem to be used for their common meaning, and for "a couple / yoke of bullocks / cows".
Barrenechea (Barrenetxea), (Jose) Mariano: Alboka: entorno folklórico (Colaboración de P. Jorge De Riezu), Bilbao, 1976, p.167.
ws (linguistics [➺ Dictionaries, &c.])