The Greek verb diaprio literally means to saw through or cut asunder. Metaphorically it describes being 'cut to the quick' — deeply infuriated or provoked to the core of one's being. In Acts it describes the violent inner reaction of those who opposed Stephen and Paul.
Both times diaprio appears in Acts (5:33; 7:54), it describes the murderous rage of the Sanhedrin against the apostles. Stephen's proclamation of the Gospel and the history of Israel's rebellion produced this visceral, violent reaction. The word captures how the truth of God can provoke the worst in fallen human nature. Yet it is the same reaction that ultimately led to Stephen's martyrdom and the spread of the Gospel.