Here's what rhymes with polysynthetic.
synthetic fetich aesthetic acetic ascetic esthetic poetic sympathetic athletic pathetic phonetic emetic hermetic parenthetic bathetic magnetic genetic energetic kinetic prophetic anesthetic cosmetic anaesthetic apathetic biosynthetic empathetic frenetic kinesthetic antithetic homiletic gametic unaesthetic exegetic phrenetic arithmetic diabetic alphabetic diuretic parasympathetic photosynthetic prosthetic unsympathetic cybernetic dietetic geodetic splenetic nonathletic unesthetic copacetic paramagnetic antipathetic apologetic phylogenetic antidiuretic ferromagnetic geomagnetic ontogenetic peripatetic nonmagnetic telekinetic psychokinetic unapologetic pharmacokinetic onomatopoetic electromagnetic Words that almost rhyme with polysynthetic
medic paramedic ferric septic hectic sceptic authentic endemic metric relic aseptic centric peptic eutectic phrenic skeptic steric derrick inauthentic pectic systemic eccentric majestic pelvic symmetric angelic eclectic forensic ischemic numeric cleric enteric splenic technic allelic benthic chimeric hysteric acerbic anorectic evangelic lovesick irenic unauthentic domestic electric generic antiseptic asymmetric concentric epistemic esoteric schizophrenic isometric obstetric polemic eugenic isomeric pandemic totemic turmeric anorexic dyspeptic leukaemic thermometric redbrick dyslectic academic atmospheric epidemic dialectic dielectric geometric antigenic epileptic mesenteric pathogenic econometric psychometric transgenic barometric biogenic colorimetric egocentric ethnocentric monomeric neurogenic neuroleptic photometric psychedelic psychogenic pyogenic tartaric alphanumeric dyslexic geocentric geodesic ionospheric neurasthenic allergenic photogenic diametric paregoric calisthenic cliometric callisthenic parametric volumetric carcinogenic cryogenic iatrogenic isoelectric mutagenic trigonometric androgenic apoplectic heliocentric radiometric cataleptic polytechnic hypoallergenic narcoleptic nonelectric telegenic photoelectric anthropogenic teratogenic hallucinogenic nonacademic paraplegic pyrotechnic hydroelectric nonparametric piezoelectric stoichiometric anthropocentric