A word for a massive erection brought on at random by an unexplained sexual stimulator. Ever had an unwanted boner? Ever felt that your erectile tissue feels like shooting up and making a hole in your jeans? Whenever you get an unwanted stiffie and you can't explain why then you know you got a Uren.
'Jeez, I just got a massive Uren! Wish it'll go!
by koismb March 06, 2013