Tubular rhymes with:
globular, angular, annular, avuncular, binocular, cardiovascular, cellular, circular, curricular, equiangular, extracurricular, gastrovascular, globular, granular, intercellular, intermolecular, irregular, jocular, jugular, molecular, muscular, particular, perpendicular, popular, rectangular, regular, secular, semicircular, singular, spectacular, testicular, triangular, unicellular, unpopular, unspectacular, vascular, vehicular, vernacular
Tubular sounds like:
tabler, tableware, tipler, tobler, toffler