From Longman Dictionary of Contemporary Englishegregiouse‧gre‧gious /ɪˈɡriːdʒəs/ adjective formal SERIOUS SITUATIONan egregious mistake, failure, problem etc is extremely bad and noticeable —egregiously adverb
Examples from the Corpus
egregious• The outcome of childbearing by both teenagers and older women can be egregious.• Why should people who do something truly egregious be protected by an arbitrary limit on their punishment?• It was an egregious breach of protocol.• The situation at Zefco was one of the most egregious examples of discrimination we have seen.• The legal system currently punishes the most egregious forms of child abuse and neglect, but such crimes are difficult to prove.• At last, to my right, the hand of an egregious front-row person rose.• This egregious nonsequitur requires further clarification, if only for your myriad younger readers.Origin egregious (1500-1600) Latin egregius “unusual”, from grex “group of animals”