Nigerian rhymes with:
algerian, algerian, assyrian, berberian, biospherian, criterion, derderian, hanoverian, hyperion, iberian, illyrian, liberian, presbyterian, quirion, shakespearean, siberian, syrian, thraco-illyrian, valerian, zairian
Nigerian sounds like:
nagorno, najarian, nanogram, nazarian, negrin, negron, negroni, newsroom, nygren