Reilly

Part of speech: noun

Definitions

1. A surname of Irish origin commonly used as a family name and occasionally a given name
2. A proper noun referring to persons or characters bearing this traditional Celtic family designation
3. An Anglicized Irish last name often associated with Celtic heritage and identity

Etymology: Reilly is an anglicised form of the Irish surname Ó Raghallaigh, which means "descendants of Raghallach." The prefix "Ó" meant "grandson of" or "descendant of," so the name originally identified a family by its ancestor. Raghallach itself is the personal name at the root, and the surname was built on it in the same way that Irish families across the country took names from notable forebears. Over time the spelling shifted to suit English speakers. The Irish "Ó" was dropped, and the rest of the name was rendered phonetically in English letters, which is why the modern form looks so different from its Irish original. Many Irish surnames went through this process, so the change reflects a general pattern in how Gaelic names entered English-speaking records rather than anything specific to this family alone.