Denmark's rhymes with:
benchmark's, benchmarks, birthmarks, bismarck's, caremark's, cellmark's, deutschemark's, deutschemarks, earmarks, hallmark's, hallmarks, hartmarx, landmark's, landmarks, pathmark's, raymark's, southmark's, trademarks, watermarks, westmark's
Denmark's sounds like:
d'america, d'amore's, dahmer's, damaris, danners, demarais, demarche, demarchi, demarco, demarcus, demaris, demark, demars, demarsh, demarzo, demeanors, demers, demerse, demirag, demory's, demurs, denarius, deniro's, denmark, didemeyer's, dimarco, dimarzio, dimarzo, dimmers, dinars, diners, dinners, ditmars, donor's, donors, donors', downers