What is the meaning of severe?

adjective

• Intensely or extremely bad or unpleasant in degree or quality.
  • usage: "severe pain"; "a severe case of flu"; "a terrible cough"; "under wicked fire from the enemy's guns"; "a wicked cough"
  • synonyms: terrible, wicked
• Very strong or vigorous.
  • usage: "strong winds"; "a hard left to the chin"; "a knockout punch"; "a severe blow"
  • synonyms: hard, knockout
• Severely simple.
  • usage: "a stark interior"
  • synonyms: austere, stark, stern
• Unsparing and uncompromising in discipline or judgment.
  • usage: "a parent severe to the pitch of hostility- H. G. Wells; "a hefty six-footer with a rather severe mien"; "a strict disciplinarian"; "a Spartan upbringing"
  • synonyms: spartan
• Causing fear or anxiety by threatening great harm.
  • usage: "a dangerous operation"; "a grave situation"; "a grave illness"; "grievous bodily harm"; "a serious wound"; "a serious turn of events"; "a severe case of pneumonia"; "a life-threatening disease"
  • synonyms: dangerous, grave, grievous, serious, life-threatening
• Very bad in degree or extent.
  • usage: "a severe worldwide depression"; "the house suffered severe damage"