rectal rat Share definition Flag An individual who has secreted his facial probiscus so far up his boss' rectum that he can gargle his boss' uvula. Did you see how that snivelling little rectal rat, Sullivan, was gobbling the boss' bone? rectal rat by Cracky Henry June 20, 2008 0 0 Get merch Get the rectal rat mug. Buy Now — $32.95 See more merch