galomp
A sneaky attack from behind or the side. Usually happens when the victim is too busy being a clueless moron to notice it coming.
I was eating a taco and my buddy galomped me like I was a hot dog at a barbecue.
During the math test, my friend galomped me so hard I spilled my coffee on the teacher.
At the mall, some kid galomped me and took my last sneaker.