Idiotic rhymes with:
antibiotic, patriotic, semiotic, symbiotic, unpatriotic, antibiotic, aquatic, astronautic, chaotic, despotic, erotic, exotic, hypnotic, narcotic, neurotic, patriotic, psychotic, quixotic, robotic, semiotic, symbiotic, unpatriotic
Idiotic sounds like:
idaho's, idea's, ideas, idec, idiocy, idiots, iodice, iodide's, iodides, it's, itasca, itch, itches, itchy, itek, ithaca, ithaca's, ito's, itochu, its, itsy, itzhak