Insistent; steadfast; urgent.

And he said unto them the third time, Why, what evil hath he done? I have found no cause of death in him: I will therefore chastise him, and let him go. And they were INSTANT with loud voices, requiring that he might be crucified. And the voices of them and of the chief priests prevailed. ( Luke 23:22-23 )

Dictionary of Words from the King James Bible. Public Domain. Copy freely.