Here's what rhymes with sardonic.
tonic harmonic ionic sonic conic phonic bionic chronic ironic chorionic demonic iconic isotonic laconic platonic daemonic acetonic tectonic colonic mnemonic hypertonic monotonic polyphonic symphonic diatonic subsonic hydroponic avionic electronic embryonic hegemonic ultrasonic supersonic diachronic histrionic planktonic synchronic catatonic telephonic monophonic philharmonic ganglionic architectonic stereophonic infrasonic quadraphonic quadrophonic pathognomonic microelectronic Words that almost rhyme with sardonic
atomic comic genomic anatomic autonomic diatomic agronomic subatomic economic ergonomic astronomic tragicomic taxonomic uneconomic gastronomic socioeconomic macroeconomic microeconomic topic boric logic toxic carbolic folic gothic tropic atopic biotic robotic bardic hayrick rollick historic symbolic cosmic aortic aquatic chaotic erotic garlic caloric caustic melodic narcotic systolic idiotic isotopic phenolic pyloric euphoric formic frolic gnostic iambic karmic meiotic myopic orthodontic sclerotic thrombotic cirrhotic rhapsodic seraphic strophic subtopic chopstick carsick subtropic shambolic placekick horologic periodic apostolic exotic hydraulic neurotic philosophic biologic despotic diastolic episodic geologic hypnotic isotropic pathologic psychotic ascorbic hyperbolic necrotic parabolic psychologic semiotic spasmodic symbiotic agnostic anabolic anarchic anoxic basaltic cathodic cytologic dialogic fibrotic hypoxic lethargic meteoric nontoxic antarctic bucolic diabolic folkloric hierarchic homoerotic vitriolic acrostic ecologic heartsick allegoric sophomoric theosophic aetiologic alcoholic metabolic patriotic physiologic cytotoxic histologic neurologic etiologic metaphoric morphologic synoptic yardstick cathartic oligarchic pedagogic polymorphic psychotropic arthroscopic demagogic xenophobic subarctic nonnarcotic chocoholic seismologic shopaholic astronautic chocaholic diagnostic antibiotic hydrochloric prehistoric catastrophic philanthropic prognostic anisotropic atherosclerotic endoscopic metamorphic pharmacologic hematologic melancholic peristaltic quixotic telescopic fluoroscopic kaleidoscopic unpatriotic gyroscopic misanthropic stroboscopic workaholic macrobiotic posthypnotic haematologic noncaloric gynaecologic microscopic macroscopic immunologic gynecologic stereoscopic microcosmic nonalcoholic meteorologic anthropomorphic spectroscopic antispasmodic submicroscopic electroscopic epidemiologic bacteriologic