substantive

(noun) any word or group of words functioning as a noun.

(adj) having a firm basis in reality and being therefore important, meaningful, or considerable. Synonyms: substantial. Example: "Substantial equivalents."

(adj) defining rights and duties as opposed to giving the rules by which rights and duties are established. Synonyms: substantive (vs. adjective), essential. Example: "Substantive law."

(adj) being on topic and prompting thought. Synonyms: meaty. Example: "A meaty discussion."