Also interpreted as 'a friend of' . Ullo means owl literally and anyone so addressed is implied to be foolish. Thus a friend of one is also implied to be as foolish if not more :)
Essentially a Hindi/Urdu phrase common in northern India:
A trip to a grocery store, convenience store, or gas station for the sole purpose of buying an excessive amount of junk food and sugary drinks, usually with friends. A chud run often happens late at night and ends with everyone involved hating themselves afterwards.