Best definition
A history or alternate history fan who is firmly entrenched in the belief that Nazi Germany’s Wehrmacht was the best

military in history, without a single flaw. Effectively, a Wehraboo is any obsessive Wehrmacht fanboy/fangirl who doesn’t like historical facts getting in the way of his militaristic fantasies. While not necessarily, many Wehraboos can become Nazi apologists. The cliché of German Techwank can be a common fetish for many Wehraboos.Based on the similar-sounding term “weeaboo” (a catch-all definition for Japanophiles).

He’s convinced that German WW2 pilots were the greatest pilots of all time.

Yeah, don’t mind his nonsense, he’s a Wehraboo.

Wehraboo: define #2
A person who is absolutely obsessed with German WWII culture.

Erwin from Girls und Panzer.

Wow, Hans is such a Wehraboo.