A car of this brand, reputably high performance and expensive.
"He saved his entire bonus to buy a sleek Porsche that he knew would thrill him on every twisty road."
In plain English: A Porsche is a famous brand of high-performance sports car known for being fast and expensive.
"I saved enough money to buy my first Porsche last year."
A surname, from German.
"The Porsche family has lived in Stuttgart for several generations."
The word Porsche comes directly from the German surname of its founder, Ferdinand Porsche. It entered English as a brand name for automobiles bearing his family name.