sunathroizo describes bringing people together, whether already gathered in a house or summoned before a speech.

The two occurrences show people brought together: a group already gathered for prayer in Acts 12:12 and men brought together before a speech in Acts 19:25.

1. People brought together in a group · dominant

   In Acts 12:12, the perfect passive participle describes many people already gathered at Mary’s house, where the APB renders the clause “many were gathered together and praying.” In Acts 19:25, the aorist active participle describes bringing together men and workers before the speaker addressed them; the APB renders “After assembling these men and the workers.”

   Acts 12:12Acts 19:25

In the Anselm Project Bible: The APB presents the group as “gathered together” in Acts 12:12 and the act as “assembling” men and workers in Acts 19:25. These are verse-level renderings rather than definitions.