Read 10 Words for People Who Are Bad At What They Do : Plater (merriam-webster.com)
Don't quit your day job
Patzer is such a great word. I’ve only heard it in context in the movie Searching for Bobby Fisher. 

Most of the others I’ve heard as well, though many are rarer. Throttlebottom is a solid one that I wasn’t aware of before, but seems very fitting. I’m half-tempted to change the tagline of my website to Philologaster now.

The Hidden Player

Thomas Henry Huxley