adverb (r)

• in a serious manner(adv.all)

  Example:
  A play dealing seriously with the question of divorce.
  

  Synonym:
  earnestly, in earnest, weightily
  

  source: wordnet30
• to a severe or serious degree(adv.all)

  Example:
  Was seriously ill.
  

  Synonym:
  badly, gravely, severely
  

  source: wordnet30