Definition of pestilent in English:

pestilent

Pronunciation /ˈpestələnt/ /ˈpɛstələnt/

adjective

  • 1Destructive to life; deadly.

    ‘pestilent diseases’
    • ‘The rise of fast growing slum quarters in cities, foul smelling, pestilent, disease ridden places where workers lived out short lives while working long hours, swelled with the dispossessed tenant farmers.’
    • ‘The Duke's affliction is first reported by the doctor as a ‘very pestilent disease.'’
    1. 1.1informal, dated Causing annoyance; troublesome.
      • ‘they are bickering like pestilent children’
      • ‘Grimble, once he's given the blessed footwear by his pestilent fairy godmother, has a smooth ride, which means no drama.’
      • ‘It's funny how life can oftentimes be like a pestilent 15-year-old.’
      annoying, irritating, infuriating, exasperating, maddening, troublesome, bothersome, tiresome, irksome, vexing, vexatious
    2. 1.2archaic Harmful or dangerous to morals or public order; pernicious.
      ‘the pestilent sect of Luther’
      • ‘Presidents come and Presidents go, but pestilent enemies of America will always be lurking, probing for cracks in our foundation.’
      • ‘The garbage strike isn't merely a glib metaphor for an economically as well as emotionally pestilent environment, however.’
      plague-like, contagious, communicable, epidemic, pestilent, dangerous, injurious, harmful, destructive, virulent, pernicious

Origin

Late Middle English from Latin pestilens, pestilent- ‘unhealthy, destructive’, from pestis ‘plague’.