The word comes from a title for the Japanese shogun
When it spiked: February 24, 2016
Definition – a businessman of exceptional wealth, power, and influence
Lookups for tycoon surged after multiple reporters used the word in their accounts of Donald Trump’s Nevada caucus victory.
The word was imported from Japan in the late 1850s, and its original meaning had very little to do with business. The Tycoon (often spelled Tykoon) was the title of the shogun, Japan's hereditary military dictator.
Tycoon is taken from the Japanese taikun, which comes from the Pekingese ta ("great") and chün ("ruler"). We begin to see it used in English around the middle of the 19th century:
On the 3d of August Her Majesty’s ships Furious, Retribution, Lee (gunboat), and steam-yacht Emperor, destined as a present for his Majesty the Tycoon of Japan, entered the port of Nagasaki, and steaming past the point at which a line of junks have heretofore been moored to bar the ingress of foreign ships, cast anchor immediately off the city and Dutch factory of Decima.
—The Times [London, England], 2 November 1858
The party was escorted to the Temple of San-Shoek-Jel, the temporary residence provided for Mr. Harris and suite; but he is to be allotted a temple near to the district in which the Tykoon or Spiritual Emperor lives.
—The Weekly Gazette [Vincennes, IN], 29 October 1859
The word quickly took on an extended meaning, and by the early 1860s was being used to refer to a noteworthy or important person. By the early 20th century it had become synonymous with magnate, the sense in which it is overwhelmingly used today.