Possibly a short form of Alonzo, the American English form of the Spanish name Alonso. Alonso is in turn a Spanish variant of Alfonso, which comes from a Visigothic name meaning 'noble and ready.'
Nicknames
lon · zo
Vibe
cool
How it ages.
Casual and contemporary - a short, nickname-style name most parents will read as modern rather than traditional.
The cultural moment.
Rare in the United States and in Germany, where it appears occasionally as a modern given name.