grievous
adjective /ˈɡriːvəs/
  /ˈɡriːvəs/
(formal)- very serious and often causing great pain or difficulty- He had been the victim of a grievous injustice.
 Oxford Collocations DictionaryGrievous is used with these nouns:- error
- sin
 Word OriginMiddle English: from Old French greveus, from grever ‘burden, encumber’, based on Latin gravare, from gravis ‘heavy, grave’.