When someone is utterly inept at producing anything that could be considered musical from a stringed instrument (such as a banjo, cello, guitar, harp, lute, ukulele, violin, etc.). This applies to those whose musical repertoire extends no further than the one time they learned how to play a Nintendo game's theme song from a Youtube video.
"I mean, I can play 'Twinkle Twinkle Little Star', but other than that, I'm strilliterate."
"I DO know how to play more than 'Gerudo Valley'. Come on, I'm not strilliterate!"
Pajama casual is a term used when working from home and preparing for a video conference. All business above the waist and your pajama pants down below.