The term 'Sinjoren' is sometimes used as the collective noun for the inhabitants of the Belgian city of Antwerp. The word is derived from the Spanish "Senor" and is a link to that period of Antwerp's history, (the 17th century), when the city was ruled by Spanish lords.

Strictly speaking, not every Antwerpian can call themselves a 'Sinjoor'. To qualify; you, your father and his father must all have been born in a certain medieval quarter of the city.

It's a bit like the Belgian version of 'cockney', I guess.