Copulate rhymes with:
depopulate, populate, depopulate, manipulate, populate, stipulate, accumulate, articulate, calculate, circulate, coagulate, depopulate, emulate, formulate, innoculate, inoculate, manipulate, miscalculate, overregulate, populate, recalculate, reformulate, regulate, reregulate, speculate, stimulate, stipulate, strangulate, tabulate
Copulate sounds like:
cabled, capability, capaldi, capaldo, cappelletti, casebolt, caufield, chavalit, civiletti, civility, cobalt, cobbled, cockfield, coffelt, coffield, cofield, copilot, coupled, covalt, covault