Diameter rhymes with:
parameter, accelerometer, altimeter, anemometer, densitometer, dynamometer, estimator, fluorometer, goniometer, hydrometer, hygrometer, interferometer, kilometer, magnetometer, micrometer, odometer, parameter, perimeter, polarimeter, spectrometer, speedometer, streitmatter, strittmatter, thermometer
Diameter sounds like:
d'andrea, dandrea, deandrea, demeter, demetre, demetria, demetrio, demetriou, denature, denominator, denture, detonator, dewinter, dimitri, dmitri, domtar, donder, dondero, dundore, dynamometer