Enwau cyfystyr ar gyfer Seona mewn gwahanol wledydd ac ieithoedd: Asia, Gianna, Giovanna, Giovannetta, Hanna, Hanne, Hannele, Hannie, Ioana, Ioanna, Iohanna, Ivana, Jana, Jane, Janina, Janna, Janne, Jean, Jeanne, Jehanne, Jennigje, Jo, Joan, Joana, Joanie, Joaninha, Joann, Joanna, Joanne, Joasia, Joetta, Joey, Johana, Johanna, Johanne, Johanneke, Johnna, Jojo, Joleen, Jolene, Jone, Jonelle, Jonette, Joni, Jonie, Jonna, Jóhanna, Jóna, Jovana, Juana, Juanita, Siobhán, Siwan, Tajuana, Vanna, Xoana, Yana, Yanka, Yanna, Yoana. Cael Seona mewn ieithoedd eraill.
Cyfenwau cyfystyr ar gyfer Macwilliam mewn gwahanol wledydd ac ieithoedd: Mac uileagóid, Mcelligott, Wilcox, Wilkerson, Wilkie, Wilkins, Wilkinson, Willems, Willemse, Willemsen, William, Williams, Williamson, Willis, Wilms, Wilson. Cael Macwilliam mewn ieithoedd eraill.