Definition of primus motor in English:

primus motor

noun

rare
  • The original source of motion or action; the cause, instigator, prime mover.

Origin

Late 16th century; earliest use found in Thomas Lodge (1558–1625), author and physician. From post-classical Latin primus motor, lit. ‘first mover’ from classical Latin prīmus + mōtor.

Pronunciation

primus motor

/ˌpriːməs ˈməʊtɔː//ˌprʌɪməs ˈməʊtə/