Gaarder rhymes with:
ardor, carder, harder, larder, marder, yarder, ardor, boarder, border, camcorder, carder, corder, crossborder, dedeurwaerder, disorder, gorder, harder, herder, larder, marder, norder, order, recorder, reorder, snowboarder, vanorder, warder, weirder, yarder
Gaarder sounds like:
garter, girder, gorder, gortari, gorter, grader, grater, greater, greditor, greedier, greider, grether, grider, grieder, gritter, grotheer, gryder