Noun

1. The attitude or belief that a particular doctrine, culture, or social system, particularly a religious or political one, is superior and that it will or should triumph over all others.
2. Excessive expression or demonstration of glee at the defeat or failure of a rival; brazen gloating.

Quotations

1994 But not only did Soviet triumphalism eventually provoke the Reaganite reaction in the United States, but, Kissinger suggests, it produced the over- extension of Soviet resources that led directly to economic and ultimately political collapse.
Michael Howard, in Foreign Affairs

2001 A better understanding of science should lead not to triumphalism but to the kind of humility recently expressed by Nobel Prize-winning geneticist Francois Jacob in Of Flies, Mice and Men: "Science cannot answer all questions. . . . It can, however, give some indications, exclude certain hypotheses. Engaging in the pursuit of science may help us make fewer mistakes.”
Jon Beckwith, in American Scientist Online

2001 One reason why triumphalism about the fall of the Taliban should be eschewed is because the US and its allies have shown insufficient regret and sadness at the deaths of Afghan villagers. This has allowed the propagandists of Islamic nihilism to claim that the US cares about the deaths of civilians in New York but not in Afghanistan.

The Independent, online news, UK

2004 Yet in addition to being self-defeating, sectarian triumphalism undermines core Jewish values of common peoplehood and mutual bonds between Jews worldwide.

Steven Bayme, in The Jewish Week

2004 The abasement rituals at Abu Ghraib were most generally conditioned by the climate of impunity created by triumphalist strategy, ideology and rhetoric, which led, at least, to dismissive negligence and then cover-ups by authorities.

Dr. Michael A. Weinstein, in The Power and Interest News Report

2008 The several answers to the charge of triumphalism might start with a basic fact of Anglo-American constitutional history: that the power, first of the Crown and now of the Executive Branch of the United States, is necessarily limited by habeas corpus jurisdiction to enquire into the legality of executive detention. And one could explain that in this Court’s exercise of responsibility to preserve habeas corpus something much more significant is involved than pulling and hauling between the judicial and political branches.
Boumediene v. Bush, 553 U.S. ___, ___ (2008) (Souter, J., concurring).