|1.||(formerly) an extended tour through the major cities of Europe, esp one undertaken by a rich or aristocratic Englishman to complete his education|
|2.||informal an extended sightseeing trip, tour of inspection, etc|
A comprehensive tour, survey, or inspection. For example, They took me on a grand tour of their new house, or The new chairman will want to make a grand tour of all the branches. Starting in the late 1600s this term was used for a tour of the major European cities, considered essential to a well-bred man's education. In the mid-1800s it was extended to more general use.