pre-chup Share definition Flag The watery substance in a settled catsup/ketchup bottle. Similar to pre-cum, hence pre-chup. Damn, I have pre-chup on my hot dog again. Next time I have to shake the catsup bottle. pre-chup by Scott Root October 27, 2006 0 0 Get merch Get the pre-chup mug. Buy Now — $32.95 See more merch