Wilbur's family nickname "Ullam" was derived from Jullam, the German word for
William. It may have been what his maternal grandparents called him, since John
Koerner was a German immigrant. Katharine had two nicknames, "Swes" and "Sterchens,"
both derived from the German word schwesterchen, meaning little sister.
Orville's nickname "Bubs" or "Bubbo" was as close as 4-year-old Wilbur could
come to pronouncing the word "brother" in 1871.
Wright Brothers Nicknames