the long boring ass book of useless words that are printed in really small font on thin paper pages, and stuff everyones grandparents would read for fun in their teenage years.
A dictionary that is typically used by college students. It does claim to be the most descriptive dictionary in the world, but it not only misses several non-slang words currently used, it even erases old definitions of words which are still being used today, in addition to avoiding technical definitions.
The ghost of Daniel Webster that rolls over in his grave for each entry in the Urban Dictionary. He causes the hair to stand up on the back of your neck everytime you lookup a word/phrase and typically a chill is felt.