Grandnephews rhymes with:
nephew's, nephews, nephew's, nephews, curfews, nephew's, nephews, argues, ceausescu's, compus, continues, curfews, debuts, donoghue's, eigenvalues, gorguze, mathews, matthew's, matthews, menus, nephew's, nephews, undervalues, values, values', w's, w.'s, w.s