a-sas'-inz (sicarioi; the King James Version murderers): Josephus (BJ, II, xiii, 3, xvii) relates that "there sprang up in Jerusalem a class of robbers called Sicarii, who slew men in the daytime, and in the midst of the city. This they did chiefly when they mingled with the populace at the festivals, and, hiding short daggers in their garments, stabbed with them those that were their enemies. The first to be assassinated by them was Jonathan the high priest, and after him many were slain daily" (see also Ant,XX , viii, 6, ix). The name is derived from Latin sica, "a dagger." The sicarioi were implacable in their hatred to Rome and to those Jews who were suspected of leaning toward Rome. They took a leading part in the Jewish rebellion and in the disturbance previous to it, and also in the faction quarrels during the war. After the war they continued their nefarious practices in Egypt and Cyrene whither they had fled.
Lysias mistook Paul for `the Egyptian who .... led out into the wilderness the 4,000 men of the sicarioi' (Ac 21:38).
S. F. Hunter