Here's what rhymes with nonclastic.
clastic elastic plastic drastic mastic nonelastic monastic scholastic inelastic spastic aplastic dynastic neoplastic sarcastic thermoplastic bombastic orgiastic fantastic stochastic ecclesiastic gymnastic iconoclastic viscoelastic periphrastic enthusiastic hyperplastic hypoplastic interscholastic unenthusiastic overenthusiastic Words that almost rhyme with nonclastic
classic lactic gastric graphic frantic erratic tactic galactic slapstick traffic magic romantic static tragic fabric panic climatic pancreatic thoracic autocratic manic pneumatic rheumatic synaptic chromatic climactic phallic magmatic tannic neoclassic malefic matchstick democratic dramatic organic automatic gigantic hepatic metallic semantic aromatic ceramic dogmatic emphatic schematic somatic thematic traumatic catholic didactic ecstatic enigmatic lymphatic mechanic nomadic aliphatic asthmatic fanatic galvanic glutamic monochromatic operatic pedantic thalamic achromatic anaphylactic italic muriatic pelagic syllabic theocratic acrobatic ataxic panchromatic tyrannic nondramatic baldric priapic aerobatic dynamic demographic geographic psychiatric inorganic pragmatic volcanic barbaric charismatic enzymatic ethnographic oceanic prophylactic prostatic sporadic cephalic cinematic emblematic geriatric kinematic messianic ophthalmic panoramic pornographic presynaptic prismatic topographic angiographic heraldic holographic monosyllabic orthographic phlegmatic satanic spermatic splanchnic technocratic titanic tomographic undemocratic zygomatic antidemocratic chiropractic nonmetallic schismatic unromantic anticlimactic biographic botanic calligraphic intergalactic nondemocratic numismatic stigmatic sycophantic thermostatic undramatic phonographic unemphatic apparatchik diplomatic aristocratic bureaucratic photographic hemorrhagic metastatic pediatric axiomatic nostalgic programmatic telegraphic transatlantic tympanic cartographic diagrammatic haemorrhagic iconographic idiomatic intrahepatic lithographic orthostatic psychopathic bimetallic epigrammatic isobaric oceanographic paediatric stenographic typographic astigmatic choreographic disyllabic meritocratic plutocratic xerographic seismographic systematic problematic symptomatic hydrostatic idiosyncratic radiographic thermodynamic aerodynamic endoplasmic melodramatic postsynaptic psychosomatic stratigraphic homeostatic intrathoracic autobiographic osteopathic polysyllabic semiautomatic photostatic undiplomatic asymptomatic cytoplasmic electrostatic hypothalamic bibliographic chromatographic hemodynamic paradigmatic psychodynamic diaphragmatic posttraumatic unproblematic unsystematic cinematographic transoceanic unidiomatic homoeostatic hydrodynamic protoplasmic lexicographic crystallographic electrocardiographic electroencephalographic