In the Ptolemaic system, the outermost of the revolving concentric spheres constituting the universe, the motion of which was supposed to carry with it all the inclosed spheres with their planets in a daily revolution from east to west
primum mobile
Hyphenation
primum mo·bile
Pronunciation
Etymology
() Post-classical Latin (from Latin prīmum neuter of prīmus ‘first’ + mōbile, from mobilis ‘mobile’), translating Arabic.