grabstash Share definition Flag A synonym for the term "Fifth" in refering to an amount of alcohol. Guys, if you all pony up 5 bones, I'll be able to get a Grabstash of Jagger for the weekend. grabstash by Tmacedaddy January 3, 2009 0 0 Get merch Get the grabstash mug. Buy Now — $32.95 See more merch