Prī'mum Mōb'i-le
[Lat., first cause of motion.] (Astron.) In the Ptolemaic system, the outermost of the revolving spheres of the universe, which was supposed to give motion to all the others.
[Lat., first cause of motion.] (Astron.) In the Ptolemaic system, the outermost of the revolving spheres of the universe, which was supposed to give motion to all the others.