engine: [13] The underlying etymological meaning of engine is ‘natural talent’. It comes ultimately from Latin ingenium (source also of English ingenious) which was formed from the base *gen- (as in genetic) denoting ‘reproduction’ and meant literally ‘skill or aptitude one was born with’. Abstract meanings related to this (such as ‘ingenuity’ and ‘genius’) have now died out in English (which acquired the word via Old French engin), but what remains is a more specific strand of meaning in the Latin word – ‘clever device, contrivance’.
Originally this was an abstract concept (often used in a bad sense ‘trick, cunning ruse’), but as early as about 1300 there is evidence of a more concrete application in English to a ‘mechanical device’. The word’s modern use for ‘machine producing motion’ originates in its early 19thcentury application to the steam engine. Engineer [14] comes via Old French engigneor from medieval Latin ingeniātōr, a derivative of the verb ingeniāre ‘contrive’, which in turn came from ingenium. => gin, ingenious[engine etymology, engine origin, 英语词源]