The Big X Share definition Flag A word to use to confuse gullible PE people at DHS, especially people named Michelle. Michelle thinks there is some sort of hidden secret with the term "The Big X." In fact, The Big X was made up on the spot by Sameer and Jake. The Big X by samtheman09 February 5, 2009 0 0 Get merch Get the The Big X mug. Buy Now — $32.95 See more merch