Iefan ystyron enw gorau: Gymwys, Gyfeillgar, Lwcus, Creadigol, Sylwgar. Cael Iefan ystyr enw.
Iefan tarddiad enw cyntaf. Welsh form of John. Cael Iefan tarddiad enw cyntaf.
Iefan diminutives enw: Ianto. Cael Llysenwau ar gyfer Iefan.
Enwau cyfystyr ar gyfer Iefan mewn gwahanol wledydd ac ieithoedd: Anže, Deshaun, Deshawn, Ean, Eoin, Evan, Ganix, Ghjuvan, Gian, Gianni, Giannino, Giannis, Giovanni, Gjon, Hampus, Hank, Hanke, Hankin, Hann, Hanne, Hannes, Hannu, Hans, Hasse, Honza, Hovhannes, Hovik, Hovo, Iain, Ian, Iancu, Ioan, Ioane, Ioann, Ioannes, Ioannis, Iohannes, Ion, Ionel, Ionuț, Iván, Ivan, Ivane, Ivano, Ivica, Ivo, Iwan, Jaan, Jānis, Jackin, Ján, Jancsi, Janek, Janez, Jani, Janika, Jankin, Janko, Janne, Jannick, Jannik, Jan, Jan, János, Janusz, Jean, Jeannot, Jehan, Jehohanan, Jens, Jo, João, Joannes, Joan, Joãozinho, Joĉjo, Johan, Johanan, Johann, Johannes, Johano, John, Johnie, Johnnie, Johnny, Jón, Jonas, Jone, Joni, Jon, Jon, Jóannes, Jóhann, Jóhannes, Joop, Jouni, Jovan, Jowan, Juan, Juanito, Juha, Juhán, Juhan, Juhana, Juhani, Juho, Jukka, Jussi, Keoni, Keshaun, Keshawn, Nelu, Nino, Ohannes, Rashaun, Rashawn, Seán, Sean, Shane, Shaun, Shawn, Shayne, Sjang, Sjeng, Vanni, Vano, Vanya, Xoán, Xuan, Yahya, Yan, Yanick, Yanko, Yann, Yanni, Yannic, Yannick, Yannis, Yehochanan, Yianni, Yiannis, Yoan, Yochanan, Yohanes, Yuhanna, Zuan, Žan. Cael Iefan mewn ieithoedd eraill.
Mae'r rhan fwyaf o'r enwau cyffredin gyda cyfenw Lied: Bennett, John, Stan, Ria, Jay. Cael Enwau sy'n mynd gyda Lied.