What is Stupo?
1.
Someone that is stupid or is acting stupid.
As I am trying to make a rental car arrangement my Dad is constantly talking and I can't hear the person on the phone. My grandpa* says to my dad, "Hey, stupo shut up"...
*He's from Connecticut, maybe it's a northern saying?
See
2.
stupo some one stupider den stupid
for example hovana i a stupo ho