Definitions by Sedative

yopper 

a lot like the word chopper (fully automatic weapon,) made famous by lil wayne in his song "so dedicated"
except a yopper is a smg (sub machine gun) usually referring to a mac 11

man I be riding round with that yopper
I pop a nigga like *shhhhhh*

yopper by Sedative November 28, 2012