Today, I’m at a lost for a Spanish word beginning with the letter J that I frequently use so I’m going back to my childhood experiences in elementary school.
Most of the J words I heard used are men’s names: Juan, Jose, Javier, and Jesús.
Jesús means Jesus, as in Jesus Christ-Jesús Cristo.

When I was growing up, the neighborhood was predominately Catholic, and photos of Jesús were in most homes; with John F. Kennedy or the Pope alongside the picture.
Jesús is also a common name for Mexican boys. Most of the kids who are named Jesús shortened their name to Jess or Jessie or Chuy. I don’t think they wanted to be mistaken for Christ, as they couldn’t live up to the name.
I don’t know why Chuy is a popular nickname for Jesús, but if you had three boys named Jesús in class, it was easy to distinguish who was whom by calling one Jess, the other Jessie, and the last one Chuy.

If four boys you knew had the name Jesús, someone would specify short Jess, tall Jess, el flaco (skinny) Jess, or Jess gordo (fat Jess).
So there you have it, Jesús.