1. noun A male who is very interested in or devoted to an element of pop culture (such as a celebrity, athlete, book series, TV show, band, or movie). My brother Eric is such a Star Wars fanboy that his voicemail message is "This isn't the Eric you're looking for," like he's Obi-Wan Kenobi!
2. verb To express excessive glee and excitement over a person or thing that one likes. My brother totally fanboyed when he met his favorite football player.