substantive

As adjectives the difference between substantive and nonsubstantive

is that substantive is of the essence or essential element of a thing; as, "substantive information" while nonsubstantive is not substantive.

As a noun substantive

is a word that names a person, place, thing or idea; a noun (sensu stricto.

As adjectives the difference between substantive and insubstantive

is that substantive is nominalized while insubstantive is (nonstandard) not substantive (in any sense).

As an adjective substantive

is nominalized.

As a noun substantivity is

the state of being substantive.