🔼The name Festus in the Bible
There's only one man named Festus in the Bible. Porcius Festus succeeded Marcus Antonius Felix as procurator of Judea in about 58 AD (Acts 24:27). He remained incumbent until 62 AD, and at that time the unrest in Judea had accumulated to the point that a full fledged revolt was inevitable. The revolt broke out in 66 AD and led to the sacking of Jerusalem and the destruction of the temple of YHWH in 70 AD by general and later emperor Titus.
One of the problems that Festus inherited from Felix was the apostle Paul, who was incarcerated near the governmental palace in Caesarea. Festus tried to solve the problem by moving Paul to Jerusalem, but the problem only became bigger when Paul appealed to Caesar, which was Nero at the time (Acts 25:11). Before Paul could be shipped off, king Agrippa and his wife Bernice showed up, and Festus brought up the matter of Paul for conversation (25:14). Intrigued, Agrippa asked to hear Paul himself.
Agrippa himself was a man of learning and Paul was eager to address him (Acts 26:3-4). He quickly proved his innocence by showing that his alleged crime was to believe in principle what the Romans were obligated to believe about Julius Caesar (Acts 26:8, see Ovid, Metamorphoses XV), and whacks his hearers around the head with a quote from Titus Maccius Plautus (254 - 184 BC) via the voice of Jesus: "Saul, Saul, why are you persecuting Me? It is hard for you to kick against the goads" (Acts 26:14, Truculentus Act IV, scene 2).
Festus probably picked up on Paul's blatant acts of high-treason against the Roman imperial cult and roared his famous oxymoron: "Paul! You are out of your mind! Your great learning is making you insane!" (Acts 26:24). Upon which Paul stated his equally famous evergreen: "I'm not insane, most excellent Festus; I utter words of truth and rationality".
Agrippa realized the profundity of Paul's understanding (26:28), but decorum dictated that Paul had to be shipped to Rome (26:32). There's no telling what would have happened if Paul could have continued reasoning with Agrippa, but Paul's presence in Rome indeed changed the world at large (23:11).
🔼Etymology and meaning of the name Festus
The name Festus is the same as the common Latin adjective festus, meaning of or belonging to the holidays (as opposed to working days), and as such it came to mean Festive, Joyful or Merry.