Examples:
The meeting, in fact, put the final touches to the establishment of the first real Stock Exchange; henceforward eutaxy was to reign.
Charles Duguid, The Story of the Stock Exchange, 1901
That most excellent, harmonious eutaxy in Heaven which God himself settled from the beginning amongst the Angels, is a thing more perfect than that which we call political liberty on earth ... ,
"Trial of Lieutenant-Colonel John Lilburne," Cobbett's Complete Collection of State Trials and Proceedings for High Treason and Other Crimes and Misdemeanors, Vol. IV, 1809
Etymology:
Greek, from the Greek adjective eutaktos, "well arranged".
First use:
Early 1600s
(from dictionary.com Word of the Day, Sept. 12, 2016)