Definition: A season of incredibly overwhelming cheer; also, the most epically friendly black friday ever.
Cheermageddon is Old Navy's Black Friday theme, which is where the "most epically friendly black friday ever" comes from (which you can check out at cheermageddon.com). On the other hand, it's actually a really creative word that can and should describe the season we are now entering: the Christmas season. Let's just say that as cheerful as it may be, I'm glad that I'm staying out of shopping malls and department stores today. I'll wait for the 12 days of Christmas to be overwhelmed by cheeriness, thank you very much.
Oh, and this is pretty funny: