Grattan rhymes with:
gratton, bratten, bratton, craton, gratton, stratton, batten, batton, bratten, bratton, caton, catton, craton, fatten, flaten, flatten, gatten, gatton, gratton, hattan, hatten, hatton, latin, laton, manhattan, matton, mchatton, patane, paton, patten, patton, platen, platten, satin, slaton, slatten, slatton, staten, staton, statton, stratton, vanpatten
Grattan sounds like:
garden, gardena, gardenia, gardin, gardini, garduno, gardyne, garritano, garten, gartin, gartman, garton, gerdeman, giardina, giardini, giardino, giarratano, giordani, giordano, girardin, girten, girtman, girton, gordan, gordana, gorden, gordian, gordin, gordon, gortney, gorton, gourdine, gradation, graden, gradney, graduation, gratton, graydon, greetham, gretna, gritton, groden, grodin, groton, grutman, guardian, guardin, guardino, guertin, gwartney, gyration, gyrodyne