severe vs grievous

severe and grievous both are adjectives.

Word	Noun	Adjective	Verb	Adverb
severe	No	Yes	No	No
grievous	No	Yes	No	No

As adjectives, severe and grievous are synonyms defined as:

Other synonyms of severe include dangerous, grave, life-threatening, serious.

severe (adjective)	grievous (adjective)
causing fear or anxiety by threatening great harm	causing fear or anxiety by threatening great harm
intensely or extremely bad or unpleasant in degree or quality	shockingly brutal or cruel
severely simple	of great gravity or crucial import; requiring serious thought
very strong or vigorous	causing or marked by grief or anguish
very bad in degree or extent
unsparing and uncompromising in discipline or judgment