Oguinn rhymes with:
o'guinn, gwin, gwinn, gwyn, gwynn, gwynne, o'guinn, aswin, eldwin, gwin, gwinn, gwyn, gwynn, gwynne, lwin, mcquinn, o'guinn, o'quinn, quin, quinn, schwinn, twin, win, winn, winne, wynn, wynne
Oguinn sounds like:
o'cana, o'guin, o'guinn, o'hagan, o'kane, o'keson, o'quinn, oakman, ocain, ocana, occasion, occhino, ocean, oceana, oceania, ocon, ogan, ogoni, oguin, ohagan, okane, okano, okasan, oken, okeson, okin, okinawa, okon, oksana, okuma, okun, okuno, oquin, oquinn, osama, osamu, oshima, oshman, osman, osmena, osmium, osmon, osmun, ossman, osuna, oxen, oxman, oxygen, ozanne, ozmun, ozone, ozuna