A caucus 's a meeting of supporters or members of a political party or movement, especially in the United States. The exact definition varies among political cultures. Origin of the term The origin of the word caucus's debated, but it's generally agreed that it first came into use in the English colonies of North America. A February 1763 entry in the diary of John Adams of Braintree, Massachusetts,'s one of the earliest appearances of Caucas, already with its modern connotations of a "smoke-fil… (More on Caucus)