'Certain' in the Bible

"A certain Ananias, who was a devout man with respect to the Law and who was highly regarded by all the Jews living there,

Five days later, the high priest Ananias arrived with certain elders and Tertullus, an attorney, and they summarized their case against Paul before the governor.

Instead, they had several arguments with him about their own religion and about a certain Jesus who had died but Paul kept asserting he was alive.

Indeed, the king knows about these things, and I can speak to him freely. For I'm certain that none of these things has escaped his notice, since this wasn't done in a corner.