By Richard Holden, OED  An engine in a car or aeroplane is such
a solid, physical thing that it might be hard to imagine that
the word engine has shown much development over its history.
Instead, the history of engine is a curious one, and is a good
example of a process which is common in English nouns: the
transferral of what was once an abstract concept to something
very concrete.  This original, abstract meaning of engine in
English was ‘ingenuity, artfulness; cunning, trickery’; in the
fourteenth century, the poet John Gower could write of women
being ‘of great engyn’ in his Confessio Amantis.  From a modern
perspective this sense can seem rather surprising, but this
befits the word’s ultimate origins in the Latin word
ingenium—from which the English ingenious is also derived.  From
this sense, it was only a short step to applying engine to the
products of such ingenuity. This could be something abstract,
like a plan or plot, such as in Edward Gibbon’s ‘dark engines of
policy’. More frequently, however, e