1. To purse one's lips together, as when tasting something sour or preparing for a kiss. I caught him puckering up and moving in for a kiss out the corner of my eye, so I pretended that I was getting a phone call from my friend. The kid pucker up when he put the sour candy in his mouth.

2. To shrink in size and become wrinkled; to shrivel up. Her skin puckered up in goose pimples when she walked out into the cold night air. You have to stretch the material out so it doesn't pucker up as it dries.

3. To cause something to shrink in size and become wrinkled; to shrivel something up. In this usage, a noun or pronoun can used between "pucker" and "up." Exposure to the air puckered up the skin as the wound healed. Stop puckering your lips up like that—you look ridiculous!