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pri·mum mo·bi·le(prī′məm mō′bə-lē′, prē′məm mō′bĭ-lā′)
1. The tenth and outermost concentric sphere of the universe thought in Ptolemaic astronomy to revolve around the earth from east to west in 24 hours and believed to cause the other nine spheres to revolve with it.
2. See prime mover.
[Medieval Latin prīmum mōbile : prīmum, neuter of prīmus, first + mōbile, from neuter of mōbilis, movable (translation of Arabic al-muḥarrik al-'awwal : al-, the + muḥarrik, mover + 'awwal, first).]
primum mobile(ˈpraɪmʊm ˈməʊbɪlɪ)
1. a prime mover
2. (Astronomy) astronomy the outermost empty sphere in the Ptolemaic system that was thought to revolve around the earth from east to west in 24 hours carrying with it the inner spheres of the planets, sun, moon, and fixed stars
[C15: from Medieval Latin: first moving (thing)]
pri•mum mo•bi•le(ˈpri mʊm ˈmoʊ bɪˌlɛ; Eng. ˈpraɪ məm ˈmɒb əˌli, ˈpri-)
(in Ptolemaic astronomy) the outermost sphere of the universe, making a complete revolution every 24 hours and causing all the others to do likewise.
[literally, first moving (thing)]