substance vs solidity

substance and solidity both are nouns.

Word	Noun	Adjective	Verb	Adverb
substance	Yes	No	No	No
solidity	Yes	No	No	No

As nouns, solidity is a hyponym of substance; that is, solidity is a word with a more specific, narrower meaning than substance:

substance (noun)	solidity (noun)
the real physical matter of which a person or thing consists	the quality of being solid and reliable financially or factually or morally
a particular kind or species of matter with uniform properties	the consistency of a solid
the property of holding together and retaining its shape	state of having the interior filled with matter
the idea that is intended
the choicest or most essential or most vital part of some idea or experience
content communicating a message; what something is about
considerable capital (wealth or income)
material of a particular kind or constitution