Riley

The Irish surname Raghallaigh, anglicized into Riley, belonged to a clan from County Cavan, and somewhere along the way it picked up the English idiom "the life of Riley" — a life of ease and good humor. The name crossed from Irish-American surnames into first-name use in the late twentieth century, and from boys' column to girls' and back, until it simply lived in both. It now sits at rank 42 in the United States. Two bouncy syllables, all vowels and a soft L, pronounced exactly as spelled. Preppy, modern, and unambiguously cheerful — the kind of name you'd expect to answer to with a grin.