meaningfulness vs significance

meaningfulness and significance both are nouns.

Word	Noun	Adjective	Verb	Adverb
meaningfulness	Yes	No	No	No
significance	Yes	No	No	No

As nouns, significance is a hypernym of meaningfulness; that is, significance is a word with a broader meaning than meaningfulness:

meaningfulness (noun)	significance (noun)
the quality of having great value or significance	the quality of being significant
	a meaning that is not expressly stated but can be inferred
	the message that is intended or expressed or signified