Source : Webster's Revised Unabridged Dictionary (1913)

Jeffersonian simplicity \Jeffersonian simplicity\
   The absence of pomp or display which Jefferson aimed at in
   his administration as President (1801-1809), eschewing
   display or ceremony tending to distinguish the President from
   the people, as in going to the capital on horseback and with
   no escort, the abolition of court etiquette and the weekly
   levee, refusal to recognize titles of honor, etc.