Save Gender Masculine Usage Old Irish [1] Meaning & HistoryExpand Links Old Irish form of Riagán. Related NamesFamily Tree·Details RootríVariantRígánOther Languages & CulturesRiagán, Ríoghán(Irish) Categories king Sources & References O'Brien, Kathleen M. Index of Names in Irish Annals, available from https://medievalscotland.org/kmo/AnnalsIndex/Masculine/Riacan.shtml.