"Wonder boy" is a colloquial term used to describe a young man who exhibits special skill, talent, or abilities. There are several synonyms for this term, each with different connotations. For instance, "prodigy" describes someone who has exceptional abilities at a young age. "Whiz kid" refers to a youngster who is an expert in a particular area. "Boy wonder" has a superhero tone and is used for popular culture icons like Batman's sidekick Robin. "Genius" is a more general alternative, used for people who show outstanding intellectual and artistic aptitude. Ultimately, the synonym chosen will depend on the context and the achievements or abilities that the individual is known for.