Theon comes from the Greek root theos meaning "god." The most famous Theon was probably Theon of Alexandria, a 4th century philosopher and mathematician.Theon
I like Theon because it has the same feeling as Theo, only more complete. It doesn't sound so much like a nickname. It sounds serious and not frivolous, but I could picture it on a little kid as well.
Theon comes from the Greek root theos meaning "god." The most famous Theon was probably Theon of Alexandria, a 4th century philosopher and mathematician.