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