Italian surnames are the most difficult of all European names to research with accuracy, and this one is no exception. It basically derives from the pre 10th century words pestare-lozzo meaning "crush-bone" and as such was a name which described a "butcher". Whether this was a slaughterer of animals or somebody who caused grievious bodily harm to others is unclear. One of the latest dictionaries of surnames states that it does have the modern meaning, but the actual Italian Dictionary of Surnames by Joseph P Fuscilla states that it is one of a group which include Fracalossi, Scaccialossi and Brusomini, all of which have meanings which at best can only be described as warlike, whilst at worst they imply (quote) "unmentionable coarseness". What makes Italian names so difficult is that it is only recently that they have adopted fixed or spellings. They have always been hereditary, but individual families whilst working to the original basic design of the name would add their own version of diminutives and patronymics at each new generation. This could mean that for example Pestalozzi could become Pesticcio and then Pestilli almost at will. In addition public records like the Italian State, are also quite recent, most being from the Victorian period, five hundred years or more after the origination of surnames! Some examples of recordings are those of Salvatore Pestrichelli, at Altamura, Bari, on March 12th 1818, and Ruggiero Pestelli, at Real Saline, Fogggia, on August 21st 1850.