Jēn, often also jān, mostly translates as “potential”. Or those at the beginning of their journey. So, heirs are called jān, apprentices have the title jān, even the youngest To’asha have jān as part of their title. So the letter covers potentiality. Like the magician card in tarot or older practise of apprenticeship with a particular trade. It doesn’t specifically mean someone who is young or inexperienced, it’s more about the potential, the waiting future, so it’s primarily about potential and having the path of some journey far ahead of you.
Pronunciation for reading it is “ja”, and it’s the “j” in jet and jump. Sometimes, like in the case of certain names (e.g. Jaran), the “j” sounds like the “s” in “measure”.