crease up
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crease up
To become creased or wrinkled, as of clothing. After sitting for so long in my suit, the pants are starting to crease up.
crease something up
to get creases or folds into something that is supposed to be flat; to wrinkle one's clothing. (Very similar to messed up.) You will crease your jacket up if you don't sit up straight. I was sitting so long that I creased up my pants.