Excellent question. The term 'hamburger' comes from Hamburg in Germany, where a minced beef style dish was first created. All of our burgers are made from whole cuts of 100% British and Irish beef, with nothing added except a pinch of salt and pepper after cooking. May 21, 2018
In 1762, John Montagu, the 4th Earl of Sandwich®, invented the meal that changed dining forever. As the story goes, he was playing cards and did not want to leave the gaming table to eat. He asked for a serving of roast beef to be placed between two slices of bread so he could eat with his hands.
Our addition of "er" comes from the German language.
Someone or something from Hamburg, Frankfurt or Lich for instance, would be called a Hamburger, Frankfurter or Licher
For instance Pilsner is a type of pale lager. It takes its name from the Bohemian city of Plzen (German: Pilsen), where the world's first pale lager was produced in 1842 ...
A one time favorite of mine...
and they're actually owned by the Bitburger Group.