A person who is hopelessly obsessed with the rock band Aerosmith.
"I can't believe that Aerogeek named his firstborn child 'Cryincrazy Amazacrazy'."
Someone who likes planes/aviation/etc. to such an extent that they feud with their rivals (often violently, but more often it's just a see-who-can-mentally-warp-the-other thing) in their furious attempt to take over the world.
EX1: Ah, you're such an aerogeek!
EX2: MAYDAY! Mortal aerogeek combat!!!