Irish Gaelic surname from Flann meaning red or ruddy-complexioned; entered first-name use internationally partly through the actor Errol Flynn and the Tron: Legacy character.
Vibe
gentle
How it ages.
Short and punchy with Celtic energy; aging well on the surname-as-first-name wave.
The cultural moment.
Rising in the US, UK, and Australia since the early 2010s; now a recognizable modern choice.