1. verb ~to put the finishing touches on your appreance. Such as lip gloss, flat ironing your hair, putting on make up, etc.
2. verb ~ Can also be used to inform someone that they may need to do a few touch ups on their look. They may be looking skank but you want to tell them nicely.
On the phone with a friend: "I will be there in like twenty minutes I just need to gloss up."
To a friend in person: "Pamela you so need to go gloss up right now."