Definitions by Tiny Toon

gummerz 

When something comes as a state of shock, as if you have never seen or heard something like it.
Can also be used when you are excited.

Person 1: Yo, did you see him get dunked on.
Person 2: Gummerz!
Person 1: My thoughts exactly.

gummerz by Tiny Toon February 6, 2005