BOB GARFIELD: For academic slang’s lexicographers, citations are essential. But let's say you’re slightly heavily intoxicated and it’s 3 a.m. and you’re puzzled over the meaning of the word, say, “skank” and you’re less concerned with scholarship than street cred. You might consider The Urban Dictionary. It’s a website of modern vernacular, much of it repulsive, graphic, fanciful and wincingly uproarious. It’s so uproarious, in fact, that the 3 a.m. Urban Dictionary clicker-onner is just as likely to be drunkenly coining a neologism as seeking clarity on somebody else’s. But the site is no mere online parlor game. It is sometimes authoritative. For example, a State Department of Motor Vehicles once cited it, trying unsuccessfully to stop a driver from using H-O-E on his license plate. So what started 10 years ago as a college student’s hobby is now an evolving cultural document. Aaron Peckham was that college student. We talked to him in 2009 and he said he started the site partly out of boredom, partly to document how he and his roommates actually talked.

AARON PECKHAM: And I thought that a dictionary would be more legitimate if the definitions were written by normal people who speak the language. So all four million definitions that have been submitted to Urban Dictionary in the last 10 years were written by random people from around the world who just happened to find my website and found it missing a particular word like “skank” or something like that.

BOB GARFIELD: One of the delights and, simultaneously, one of the most appalling things about [LAUGHS] The Urban Dictionary is the level of graphic detail that you find in definitions to terms that, on the face of it, don't sound all that repulsive, and yet, you discover that, you know, a common household term or, you know, a menu item can –

[AARON PECKHAM LAUGHS] - actually refer to something that is [LAUGHS] just a bit on the off-color side. Did these things exist before you, or have they been kind of created by a subculture of people who want to be in the lexicon?

AARON PECKHAM: I can't tell if these words existed, with these meanings, before Urban Dictionary. But that’s kind of the part of the fun of visiting the site, is that a lot of the definitions are totally false. They're definitely not objective. And so, it’s really the reader’s responsibility to figure out if the definition you’re reading is relevant to you [LAUGHS], or whether it’s accurate.

BOB GARFIELD: All right now, our producer, Nazanin Rafsanjani, has a personal favorite. It is – oh, Mom, I'm sorry –

[AARON PECKHAM LAUGHS] – “food douche.”

AARON PECKHAM: “Food douche: A person that thinks they know the best place to get any one specific item of food, and that the places you know all suck.”

BOB GARFIELD: [LAUGHING] Keep reading.

AARON PECKHAM: Jason says, “I love this turkey sandwich.” Joey says, “This sandwich sucks. I know a place with the best turkey sandwich I've ever had!”

[BOB LAUGHS] Jason says, “You are such a food douche.”

BOB GARFIELD: Okay, now even that’s a little edgy. Have, have you got any that isn't going to make anybody wince?

[OVERTALK]

AARON PECKHAM: Yeah. Every day I pick one of my favorite definitions on Urban Dictionary and put it on the front page, and the other day that word was “joke insurance.” Joke insurance is when two friends have a mutual understanding to laugh at each other’s jokes, even when they're not funny.

[BOB LAUGHS] One of my other favorite definitions is “afterclap.” An “afterclapper” is the person who continues to clap even after the rest of the audience has stopped clapping.

[BOB LAUGHING] Another of my favorite definitions is “Finger guns: A way for creepy people with moustaches to say hello or ‘I understand.’ Hold your fingers in the shape of guns and point at someone who just arrived. Bend thumbs to simulate shooting your finger guns and make a clicking sound with your mouth.”

BOB GARFIELD: All right, Aaron.

[AARON PECKHAM LAUGHS] I can't take this any more.

AARON PECKHAM: [LAUGHS] I’m glad you enjoyed it.

BOB GARFIELD: Many, many thanks.

AARON PECKHAM: Thank you, Bob. It’s a pleasure to be here.

BOB GARFIELD: Aaron Peckham is the founder of Urbandictionary.com.