Assassin

is a Latin word (sicarius, "from" sica, "a dagger") denoting "one who carries a dagger or short sword under his clothing, an assassin," Act 21:38, RV. Here it is used as a proper name (see the RV) of the Sicarii, "assassins," the fanatical Jewish faction which arose in Judea after Felix had rid the country of the robbers referred to by Josephus (Ant., XX). They mingled with the crowds at festivals and stabbed their political opponents unobserved (AV, "murderers").