Jal was a name earned by young male Kazon warriors signifying their ascension into adulthood.
To earn this name, the young Kazon must have killed an enemy in battle or be killed himself, thus earning the name posthumously. Being captured by the enemy prevented the young Kazon from ever earning his adult name. Typically, a young Kazon was given a name at birth, and that name formed part of their new name when they reached adulthood - for example, Kar became Jal Karden. (VOY: "Initiations")