1. To pucker one's lips, as when tasting something sour or preparing for a kiss. I caught him pursing 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 purse up when he put the sour candy in his mouth.
2. To shrink in size and become wrinkled; to shrivel up. Her skin pursed up in goose pimples when she walked out into the cold night air. You have to stretch the material out so it doesn't purse up as it dries.
3. To cause something to contract or bunch up. In this usage, a noun or pronoun can used between "purse" and "up." Pull the two drawstrings to purse up the opening of the bag. Stop pursing your lips up like that—you look ridiculous!
purse something up
to bunch or pucker something up. (Usually the lips.) When he tasted the lemon juice, he pursed his lips up and spat it out. Don pursed up his lips as if to spit it out.