fanny flea Share definition Flag A flea that resides in the vaginal area. Very itchy and is somtimes confused with the common fanny crab. Hey caitlin, You are a fanny flea! Hey brenden go eat some fanny fleas. fanny flea by smg4eva December 3, 2006 0 0 Get merch Get the fanny flea mug. Buy Now — $32.95 See more merch