poolbag Share definition Flag Someone acting like a douchebag in a pool. Hogging up space and splashing people and such. A group of poolbags is known as a poolbag posse. Some well known OG poolbags are Mr. Sideburns and McChubs. poolbag by snipmynips July 29, 2015 0 0 Get merch Get the poolbag mug. Buy Now — $32.95 See more merch