1having a firm basis in reality and so important, meaningful, or considerable:there is no substantive evidence for the efficacy of these drugs 2having a separate and independent existence. (of a rank or appointment) not acting or temporary; permanent: he earned the rank of Substantive Corporal (of an enactment, motion, or resolution) made in due form as such; not amended. 3(of law) defining rights and duties, as opposed to giving the procedural rules by which those rights and duties are enforced.
4(of a dye) not needing a mordant.
(also noun substantive) Grammar
, dated a noun.