Irizarry is in fact a last name from the basque region of Spain. I went to Barcelona on 1995 and found the entire history of the last name in a shop. My mom should have the certificate at home in Puerto Rico. If i remember right it came from the basque name Ira-ziri, which means "Villa de Cerdos" On those times people got their names from where they lived and from what they did for a living. It turns out our family's ancestors where business people dedicated to raising farm animals and most commonly pigs. Yes we are all pig breeders ;) They were famous in the region for the quality of the meats from their animals and owned great extensions of land.
So here you have it our history in a nutshell. They later modified the name and over the years it became Irizarry.