św

In a sentence

• Święty Piotr był jednym z apostołów.

  Saint Peter was one of the apostles.

  Here, "św" is an abbreviation for "święty" meaning "Saint," and it's used to denote a revered person in a religious context.

• Ulica Św. Tomasza znajduje się w Krakowie.

  St. Thomas Street is located in Krakow.

  In this instance, "św" is used as part of a street name, standing for "święty" or "święta."

• Św. Mikołaj przychodzi do dzieci w grudniu.

  Santa Claus comes to children in December.

  Here, "św" stands for "święty," and it's used informally to refer to St. Nicholas, traditionally known as Santa Claus.