sticker
A small sticky picture or label you press onto things.
A sticker is a small piece of paper, plastic, or vinyl with a picture or words on one side and adhesive (sticky glue) on the other, designed to stick onto surfaces. Teachers put gold star stickers on excellent homework. Kids collect stickers of their favorite characters and stick them in notebooks or on water bottles. Bumper stickers on cars display messages or jokes for other drivers to read.
Stickers come in endless varieties: some are glossy and colorful, others are simple labels. Some are meant to be temporary and peel off easily, while others (like an inspection sticker on a car windshield) are designed to stay put. Laptop stickers let people show off their interests and personality. Price stickers in stores tell you what things cost.
The word can also describe someone who sticks with something no matter what. A sticker in this sense is a person who perseveres, someone who doesn't quit when things get difficult. If your coach calls you a sticker, that's high praise: it means you have staying power and determination.