To make someone or something appear more elegant, dazzling, classy, or fancy. ("Shnazz" is a variant spelling of "snazz.") A noun or pronoun can be used between "shnazz" and "up." You really should shnazz yourself up a bit if you want to make a good first impression on your date. I decided to shnazz up my outfit with a diamond necklace and some classy silk gloves. I always like to shnazz up my popcorn with a bit of cinnamon and brown sugar.