Definition of flagitious in US English:

flagitious

adjective

formal
  • (of a person or their actions) criminal; villainous.

    • ‘Such a flagitious attempt could only be made under some general pretence by a state legislature.’
    evil, sinful, immoral, wrong, morally wrong, wrongful, bad, iniquitous, corrupt, black-hearted, ungodly, unholy, irreligious, unrighteous, sacrilegious, profane, blasphemous, impious, base, mean, vile
    View synonyms

Origin

Late Middle English: from Latin flagitiosus, from flagitium ‘importunity, shameful crime’, from flagitare ‘demand earnestly’.

Pronunciation

flagitious

/fləˈjiSHəs//fləˈdʒɪʃəs/