Wiktionary
n. 1 the state of being special, exceptional or unique 2 the belief that a particular nation does not conform to an established norm 3 a philosophy of prevention or of intervention
Wikipedia
Exceptionalism is the perception that a country, society, institution, movement, or time period is "exceptional" (i.e., unusual or extraordinary) in some way and thus does not need to conform to normal rules or principles. Although the idea appears to have developed with respect to an era, today the term is particularly applied to national or regional exceptionalism. Other uses are rarer in the present day.
Usage examples of "exceptionalism".
Pilgrims, history textbooks introduce the archetype of American exceptionalism.
This is another aspect of the archetype of American exceptionalism: our society has been uniquely fair.