Hubris ( from ancient Greek ὕβρις) describes a personality quality of extreme or foolish pride or dangerous overconfidence, often in combination with (or synonymous with) arrogance. In its ancient Greek context, it typically describes behavior that defies the norms of behavior or challenges the gods, and which in turn brings about the downfall, or nemesis, of the perpetrator of hubris.
The adjectival form of the noun hubris is "hubristic". Hubris is usually perceived as a characteristic of an individual rather than a group, although the group the offender belongs to may suffer collateral consequences from the wrongful act. Hubris often indicates a loss of contact with reality and an overestimation of one's own competence, accomplishments or capabilities.