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