(derogatory,fandomslang, chiefly Transformers and Pokémon fandoms) Someone who prefers the first generation of a franchise, especially when elitist or snobbish about later generations.
2007 November 20, Kittie Rose, “This is why I don't like moderated TF boards,Somebody got named #1 TF fan.”, in alt.toys.transformers[1] (Usenet):
For every "whiny geewunner" out there, there are at least three or four anti-fans who bash, ridicule, and disparage them.
2012 February 1, Gustavo, “Gustavo mutters about Fansproject Insecticons.”, in alt.toys.transformers[2] (Usenet):
I might be becoming a bit more of a Geewunner myself -- I just don't see the point in the latest reboot (Prime), despite it being well done.
2012 July 24, Primus, “your favorite Bay movie?”, in alt.toys.transformers[3] (Usenet):
Yep. I see it as an attempt to please me, as a "geewunner." They failed, but at least an attempt was made.