1. a worthless piece of cloth, especially one that is used to wipe semen on
Garmuc is the word "cum-rag" spelled backwards. Many young men use socks, dish towels, t-shirts or what have you for this purpose. Often times it is easier for one male to say to another "I left my garmuc out!" instead of "cum rag".
"Dude, my mom did my laundry and found my garmuc!"
Friend: "Holy shit balls batman, that thing probably stood up on itself -- she is totally going to cut your internet off!"