A compound verb indicating threats piled on top of previous threats—additional intimidation beyond what was already spoken. Luke uses it in Acts 4:21 to describe the Sanhedrin after Peter and John's defense: having further threatened them, they released them. The authorities had already issued threats, now they pile on more, escalating intimidation to silence the apostles. The additional threatening reveals both the council's impotence (they can only threaten, not actually stop the preaching) and their desperation (more threats suggest the earlier ones didn't work).