telling vs weighty

telling is a noun but weighty is not a noun.

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

As adjectives, telling and weighty are synonyms defined as:

Other synonyms of telling include cogent.

telling (noun)	weighty (noun)
informing by words
an act of narration
disclosing information or giving evidence about another

telling (adjective)	weighty (adjective)
producing a strong effect	having relatively great weight; heavy
disclosing unintentionally something concealed	excessively fat
powerfully persuasive	weighing heavily on the spirit; causing anxiety or worry
	of great gravity or crucial import; requiring serious thought
	powerfully persuasive