The Greek noun burseus (βυρσεύς) refers to a tanner — a craftsman who treats animal hides with tannin to produce leather. The word derives from byrsa (animal hide/leather). It appears three times in the New Testament (Acts 9:43; 10:6, 32), each time referring to Simon the tanner in Joppa, in whose house Peter stayed and where he received the pivotal vision that opened the Gospel to the Gentiles.
Simon the tanner's significance in Acts cannot be overstated. Tanners worked with animal carcasses, making them perpetually ritually unclean by Jewish law. Peter — a devout Jew who would not eat unclean food — was staying in the house of a burseus. God's choice of this setting for the revolutionary vision of Acts 10 is pointed: in the house of a man considered unclean, Peter received a vision about not calling unclean what God has cleansed. The very location of Peter's lodging became a parable preparing him to say "yes" when Cornelius's messengers arrived. God was already at work dismantling the walls of Jewish exclusivity before the vision ever came.