An abbreviation for "crease pattern." Most often used by origami artists to share their work without revealing all the steps. Notable examples include: Satoshi Kamiya's Phoenix 3.5, and Nguyen's Eagle. Crease patterns are meant to show all the folds that will be present at the end of a particular work in a 2D format. Crease patterns are typically copyrighted so that commercial duplication/distribution is considered a punishable crime.
"Aww, this origami is insane! I can't figure out how to fold this from just a plain CP!"