When someone makes up a silly little definition you tell them that they are talking utter nonsense.
Strangley enough, the majority of definitions on Urban Dicitionary fall into that category.
Synonyms for utter nonsense
On this page, you will find 30 slang terms related to utter nonsense. Some of the top words include: talking trash, GOOSENECK, pointful, my ass, fagort, and 25 more.