Likely a modern Hebrew-style creation, often interpreted as combining divine and uplifting elements in the style of biblical names.
Calel is an intriguing name that sits at the crossroads of Hebrew linguistics and modern mythology. Scholars of Hebrew have traced the construction Kal-El — and its variant spellings including Calel — to roots meaning something close to "voice of God" or "all that is God," drawing on kal (voice, all) and El (the ancient Semitic word for deity). This etymology was deliberately invoked by Action Comics writers Jerry Siegel and Joe Shuster, themselves sons of Jewish immigrants, when they named the infant Kryptonian who would become Superman: Kal-El, a name that consciously echoed the naming conventions of Hebrew scripture.
Before Superman reframed the name for popular culture, El-compound names were ancient and sacred — El appears in names from Elijah ("my God is Yahweh") to Daniel ("God is my judge") to Michael ("who is like God"). Calel's particular form gives it a softer, more approachable feel than its mythic associations might suggest, the hard C opening into light vowels that carry easily in any language. In recent years, Calel has attracted parents drawn to names with deep roots and big resonances, names that carry narrative without being burdened by a single famous bearer.
The Superman connection brings a note of heroism and idealism, while the ancient Hebrew substrate grounds the name in something far older than comics. It is a name for someone expected to stand for something.