Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
substantiative is an adjective meaning "serving to support or corroborate". It carries one recorded sense.
serving to support or corroborate
“collateral evidence”
Definitions, synonyms and semantic relations for substantiative come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.