Here's what rhymes with additative.
dative native iterative creative appreciative imitative vegetative educative meditative radiative dissipative denotative nonnative cogitative annotative cooperative authoritative innovative collaborative associative oxidative deliberative evaporative connotative legislative quantitative qualitative integrative dissociative procreative copulative unappreciative emulative administrative evaluative interpretative manipulative regulative rehabilitative stimulative investigative accumulative nonadministrative Words that almost rhyme with additative
cages sages rages phages wadis wadges mutatis engages bellyaches reengages disengages greengages macrophages plaintive pervasive abrasive evasive invasive persuasive dissuasive unpersuasive nonabrasive noninvasive