by jingo

Etymology
for a long time. Main theories include:


 * a minced oath of "by Jesus"; compare, , , etc.
 * a corruption ultimately of "by St. Gingoulph", in reference to.
 * a borrowing from ; compare . Basque sailors ― a common famous occupation for their people, who often swore by their term for God ― travelled far through the seas for centuries, and often met Englishmen.