The story
Anglicized from Irish Gaelic Ó Riagáin (“descendant of Riagán”), a personal name possibly derived from ríodhgach (“impulsive, furious”), an alternative form of ríogach.
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: A surname from Irish; variant forms Regan, Riggen. Full definition →
Anglicized from Irish Gaelic Ó Riagáin (“descendant of Riagán”), a personal name possibly derived from ríodhgach (“impulsive, furious”), an alternative form of ríogach.
Etymology from Wiktionary, CC BY-SA 4.0.