c.1500, from L. factionem (nom. factio) "political party, class of persons," lit. "a making or doing," from facere "to do" (see factitious). In ancient Rome, "one of the companies of contractors for the chariot races in the circus."
A group formed to seek some goal within a political party or a government. The term suggests quarrelsome dissent from the course pursued by the party or government majority: “His administration is moderate, but it contains a faction of extremists.”