Guba's rhymes with:
cuba's, cuba's, dubas, kubas, lubas, amoebas, baba's, beeba's, ciba's, cordoba's, cordobas, cuba's, dubas, dybas, gibas, kubas, lubas, mambas, rebbe's, ribas, sabas, simba's, toshiba's, urbas
Guba's sounds like:
gaffes, gap's, gaps, gasps, gebbie's, gibas, gibb's, gibbs, gibbs's, gibes, giveaways, giveback, givebacks, gives, gobs, goofs, goosefish, gopac, gopac's, gossips, govpx, govs, gozofsky, guavas, guffaws, guppies, gypsies, gypsy