egregious

conspicuously and outrageously bad or reprehensible

Surpassing; extraordinary; distinguished (in a bad sense); -- formerly used with words importing a good quality, but now joined with words having a bad sense; as, an egregious rascal; an egregious ass; an egregious mistake.

Latin 'ex-' (out) + 'grues' (shocking)

“Beauty had been struck down by his egregious folly, and there he stood--a wretch!”

— George Meredith, Complete Project Gutenberg Works of George Meredith

“William Blackstone used the term for significant and egregious violations of public trust of a nature and extent that the transgression would justify a revolutionary response.”