[fan-boi]Informal: Often Disparaging.
  1. Sometimes fan·boi. an obsessive male fan, especially of comic books, science fiction, video games, music, or electronic devices:Apple fanboys lined up to buy the new phone.
verb (used without object)
  1. (of a male fan) to demonstrate intense excitement at the mention or in the presence of a particular celebrity, film, product, etc., especially one associated with popular culture or technology: I don't usually fanboy over optics, but these binoculars are awesome.

Origin of fanboy

First recorded in 1915–20; fan2 + boy
Related formsfan·boy·ing, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for fanboy

Contemporary Examples of fanboy