1) A materialist. Someone who insists on using different sorts of gear in the most unneeded of times. 2) A giermo will always buy the most on a shopping trip, or buy the most flashy/visible things. 3) Also a name for a snobby rich person.
Guermo is short for Guillermo. It also is used for a Puertorican who looks like a Mexican. They are also very fast runners from all of the escaping they do from Trump's Border Control because they are illegal immigrants.