Bible Dictionaries
Primum Mobile

Webster's Dictionary

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. See Crystalline heavens, under Crystalline.

Bibliography Information
Webster, Noah. Entry for 'Primum Mobile'. Noah Webster's American Dictionary. https://www.studylight.org/​dictionaries/​eng/​web/​p/primum-mobile.html. 1828.