Here's how you can understand it:
* Literally: It means "little senior" or "young senior." It's a playful and affectionate term used for a young man who is considered "senior" in some way, perhaps because of his age, position, or experience.
* Meaning: The closest English equivalent would be something like "young leader" or "junior executive", depending on the context.
However, the best way to translate "seniorito" depends on the specific situation. For example, if you're talking about a high school senior, you could use "senior," "senior boy," or "upperclassman."
It's best to provide more context for a more precise translation.