Definition of "Severe" :

adjective: causing fear or anxiety by threatening great harm

"A severe case of pneumonia."

adjective: very bad in degree or extent

"A severe worldwide depression."

adjective: unsparing and uncompromising in discipline or judgment

"A parent severe to the pitch of hostility."

adjective: intensely or extremely bad or unpleasant in degree or quality

"Severe pain."

adjective: severely simple

adjective: very strong or vigorous

"A severe blow."