Merciless rhymes with:
oxalis, acropolis, aeschelus, anomalous, boulalas, calculus, carolus, credulous, daedalus, deangelis, fabulous, frivolous, garrulous, heliopolis, hydroencephalus, incredulous, libelous, los-angeles, maquilas, marvelous, mcnicholas, megalopolis, meticulous, metropolis, miraculous, nautilus, nebulous, necropolis, nicholas, nicholas', nicolas, oscalus, oxalis, papadopoulos, pendulous, perilous, persepolis, populace, populous, querulous, ridiculous, romulus, scandalous, scrupulous, scurrilous, segalas, stefanopolis, stephanopoulos, stephanopoulos', stimulus, tantalus, tremulous, unscrupulous
Merciless sounds like:
marcellus, margolick, margolies, margolis, margulies, margulis, marsalis, marschalk, marseilles, marshal's, marshall's, marshalls, marshals, marsolek, marszalek, miracles, miraculous, morsels