This intensive compound verb means to refute completely or demonstrate someone's error decisively. Acts 18:28 describes Apollos who 'vigorously refuted' the Jews publicly, using Scripture to prove Jesus was the Messiah. The prefix strengthens the simple 'refute,' suggesting thorough, perhaps repeated, demonstration of error. The Spanish 'refutaba' and French 'prouver' both capture the argumentative force of this public intellectual combat.