A word originating from the Yiddish word shlepn, meaning "to drag," that is used to describe laboriously carrying something or dragging oneself on a long/tiring journey.
I had to schlep all the way across the airport just to miss my flight!
You must be really bored if you're looking up hi in Urban Dictionary. Get a life.
If somehow you actually don't know what this means it's a greeting.
Hi I'm bored so I'm searching random stuff on Urban Dictionary.