The Greek verb apotinassō means to shake off, to shake away, to dislodge by shaking. It appears in Acts for shaking off a viper into the fire (Acts 28:5) and for shaking dust off feet as a prophetic act (Luke 9:5).
Jesus instructs the seventy-two: 'Shake the dust off your feet' (apotinassete) when a town refuses the gospel (Luke 9:5) — a Jewish practice of dissociating from Gentile defilement, here turned into a sign of prophetic accountability. Those who reject the gospel bear full responsibility; the apostles are released from it. Paul enacts exactly this when the Maltese viper bites him: 'he shook it off (apetinaxen) into the fire and suffered no ill effects' (Acts 28:5) — a sign miracle recalling Jesus' promise in Mark 16:18. The word captures the NT pattern of resilience: opposition, rejection, and even snakebite cannot derail the mission. The gospel shakes off its enemies and marches on.