1.Definition: causing fear or anxiety by threatening great harm
"A severe case of pneumonia"
2.Definition: intensely or extremely bad or unpleasant in degree or quality
"Severe pain", "A severe case of flu"
4.Definition: unsparing and uncompromising in discipline or judgment
"A parent severe to the pitch of hostility", "A hefty six-footer with a rather severe mien"
5.Definition: very bad in degree or extent
"A severe worldwide depression", "The house suffered severe damage"