Yarn Vomit
Yarn vomit, also called yarn barf, is a term used in various yarn craft online spaces. It often refers to when someone attempts to pull just the center strand of a yarn skein, and in the process pulls out a large chunk of messy yarn. It can also be used in reference to any highly messy and tangled length of yarn.
"I was excited to use this yarn, but it's just become such an unworkable pile of yarn vomit. I don't think I could untangle it with a month of work."