grievous

/ˈɡriːvəs/
adjective
  1. Very serious or severe, often causing great pain or suffering.
    • The country suffered a grievous loss when the beloved leader passed away.
    • The accident caused grievous injuries to several passengers.
    • Making a grievous mistake in the report cost the company a lot of money.
  2. Very bad or shocking; used to emphasize how unpleasant something is.
    • The team made a grievous error by forgetting to check the data.
    • The movie received grievous reviews from almost every critic.
    • It was a grievous insult to ignore her after she had helped so much.
Antonyms
What does "grievous" mean? | whatsthatwordmean | whatsthatwordmean