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In Theory 

Somthing cyrus says when he doesnt know what he is talking about, nut he plays it off like he knows. Any statement that uses this phrase is usually 99 percent accurate, i dont know how.
Me-"Hey Cyrus, how will mount the tv" Cyrus-"Well.....ummm......In Theory you can get tape and hang it"
In Theory by Riazi May 21, 2018

Brother-in-theory 

A would-be brother-in-law who is in a commited relationship with your sister but isn't legally married to her.

These relatives are awkward to introduce because they're not necessarily your friends, but technically not your relatives either. You don't want to insult him by going into detail about his relationship with your sister in public, but if you call him your brother-in-law, awkwardness might arise when people glance at the non-existent wedding ring.

This also applies to would-be parents and sisters-in-law.
Jack: Hey Ted, why don't you invite your brother-in-theory onto our softball team?

Ted: Are you kidding? Then my father-in-theory's gonna want to join too. There's a reason I didn't marry into that crazy family, ya know.
Brother-in-theory by Gossip Who? September 13, 2009

Hoe in theory 

A hoe in theory means that you would be a hoe if you were
I'm a virgin but a hoe in theory
Hoe in theory by Kurb43 February 26, 2017

gay in theory 

when a person often does a stereotyped gay thing to their sex, but isn't actually gay themselves.
he's into singstar, doesn't mind shopping and puts down the toilet seat. he isn't gay, just gay in theory.

"did jack just say he's getting into interior decorating?"
"don't worry about it... he's just gay in theory."
gay in theory by Citronic January 28, 2009

Favorite (in theory) 

Well, no, I said...
Hym "That Islam was my favorite (in theory) and in the context of their rituals (Pilgrimage and praying 5 times a day). It's something I enjoy in a scholarly sense. Humans aren't good at being consistent (in thought or action) so you'll have to forgive me.
Favorite (in theory) by Hym Iam July 23, 2023

In a theory

A game theeooorrryyy
Someone”in a theory”
Me, who wasn’t listening”what?”
In a theory by codenamedoIphin December 4, 2020
More from Urban Dictionary
The phenomenon where adults salivate at children's toys
Every time I walk into the toy aisle, I catch myself kidulting over the latest action figures and LEGO sets!
kidulting by Emotional Cruiser October 12, 2025
Word of the Day on October 4, 2026
British slang for a scientist or technical expert, esp . when the speaker is not certain of the expert’s specific field of study. Not necessarily derogatory, but typically used by persons without a technical background. In the US, the equivalent would be “egghead”, “squint”, or “geek.”

Origin of the word is unknown. Started sometime in World War 2. Given the typical evolution of British slang, could easily have started because what these experts did was confusing or “baffling” to the common person.
According to the boffins downstairs, the murderer used a serrated blade.
Boffin by Agnon February 11, 2023
Word of the Day on October 3, 2026

Pee Calculus

When you have to pee in a movie but don’t want to miss anything, and must do the following mental equation: will the amount I have to pee cause enough discomfort to diminish my attention capacity for the remainder of the movie to an extent which is greater than the amount of the movie I would miss by making a mad dash to the restroom.
I saw Satantango last night, wonderful film but by the 5th hour I had to start doing pee calculus.
Pee Calculus by anorlondo October 1, 2026
Word of the Day on October 2, 2026
Literally "dirty" pronounced with a West Indian accent. Can also have a positive connotation, for example Sean Paul's album title "Dutty Rock".
"The girl is pretty but she corrupt and dutty!"

or, in a positive usage:

"Booya! That freestyle was dutty!"
Dutty by J Hall April 3, 2003
Word of the Day on October 1, 2026
korean word for madam, older woman
Ajumma wait a moment
Ajumma by aintnotinbutnice July 5, 2009
Word of the Day on September 30, 2026
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