Engine, a term applied exclusively to military affairs in the Bible. The engines to which the term is applied in 2 Chron. 26:15 were designed to propel various missiles from the walls of a besieged town. One, with which the Hebrews were acquainted, was the battering-ram, described in Ezek. 26:9, and still more precisely in Ezek. 4:2; 21:22.