of import vs grievous

of import and grievous both are adjectives.

Word	Noun	Adjective	Verb	Adverb
of import	No	Yes	No	No
grievous	No	Yes	No	No

of import (adjective)	grievous (adjective)
of great significance or value	causing fear or anxiety by threatening great harm
	shockingly brutal or cruel
	of great gravity or crucial import; requiring serious thought
	causing or marked by grief or anguish