grievous vs weighty

grievous and weighty both are adjectives.

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

As adjectives, grievous and weighty are synonyms defined as:

grievous and weighty: of great gravity or crucial import; requiring serious thought

Other synonyms of grievous include grave, heavy.

grievous (adjective)	weighty (adjective)
causing fear or anxiety by threatening great harm	having relatively great weight; heavy
shockingly brutal or cruel	excessively fat
of great gravity or crucial import; requiring serious thought	weighing heavily on the spirit; causing anxiety or worry
causing or marked by grief or anguish	of great gravity or crucial import; requiring serious thought
	powerfully persuasive