A fellow citizen that obeys the laws and respects the rules and guidelines put forth by society. This person is also very helpful and has good morals.
Dude 1: "Dude, you stopped chewing tobacco and drinking and driving?"
Dude 2: "Yeah man, I realized how it was harmful to my health and how I was putting others in risk."
Dude 1: "Wow dude! You've really turned into a genuine upstanding citizen!"
Dude 2: "Heeelllla upstanding!"
You are at the playground and someone comes over and starts to trash talk about you. There are a crowd of bystanders but no one will help you stand up tothe bully. The one person who does stand up will you to the bully is the upstander.