Sixteenth rhymes with:
eighteenth, fifteenth, fourteenth, nineteenth, seventeenth, thirteenth, eighteenth, fifteenth, fourteenth, nineteenth, seventeenth, thirteenth
Sixteenth sounds like:
saddened, sectioned, sediment, stained, stamand, stamant, stamaty, stand, standa, standout, stant, stanwood, statement, stationed, steamed, stemmed, stennett, stent, stinnett, stinnette, stint, stomata, stoned, student, stunned, stunt, stunted, stymied, sustained, sweetened, systemat, systemwide