Feminine form of Carl/Charles, from Germanic 'karl' meaning 'free man' or 'strong'.
Carlena is a feminine elaboration of Carl and its Romance-language cousins Carlos and Carlo, all tracing back to the Germanic personal name Karl. The etymology of Karl is debated but most convincingly points to a Proto-Germanic root meaning "free man" — one who was not a serf — and in some analyses to a related sense of "strong man" or "husband." The name's most famous bearer, Charlemagne (Carolus Magnus — Charles the Great), so dominated medieval European history that his Latin name became the template for "king" in several Slavic languages.
Carlena belongs to the broad family of feminine forms constructed from this root — Carolina, Carla, Carlotta, Charlene, Karoline — that spread across Europe and the Americas as the Carolingian legacy filtered down through ecclesiastical and aristocratic naming culture. Carlena itself represents a specifically American elaboration, the kind of name that gained currency in the mid-twentieth-century United States, where adding a melodic -lena or -leen suffix to established names was a living folk-naming practice. It sits alongside Marlena, Arlena, and Darlena in this informal tradition.
The name carries a mid-century American warmth — the sound of a name written in a church register in Georgia or Louisiana in the 1940s or 1950s, belonging to a woman who was called Carlie at home. It has not returned to fashion in the way that some vintage names have, which gives it a pleasingly unhurried quality: Carlena doesn't know it's supposed to be having a moment, and that unselfconsciousness is its own kind of charm.