Thatone 

"That" and "one" put together. Used when referring to something that needs to be pointed out. Thatone stands alone as a noun, and should not be used as an adjective (refer to incorrect usage)

Similar to: Whatnot, alright, maybe

Person 1: Which one should I get?
Person 2: Thatone looks better.

Oh, yeah, I missed thatone.

Incorrect usage:
Thatone thing ruins it.

Thatone by NBKah December 29, 2009

ThatOneFormula 

A F1 YouTuber who post F1 Meme and Info Videos on YouTube.

Did you saw the latest ThatOneFormula Video?

ThatOneFormula by Kg1354 March 6, 2021

Thatonlybritishspider 

A nice, talented teenager who likes voice acting over the spiderverse but also other fandoms! He's mostly known for his really good interpretation of Hobie Brown's voice and accent. His fanbase is loving and we adore him for the sweet and funny personality.

He dreams of big screens in the future!

Go follow @thatonlybritishspider on tik tok!! You'll sure enjoy his content

Thatonlybritishspider by ioana (ioaqna on tik tok!!) August 30, 2023

I felt that one! 

An ejaculation of pain, suffering, or commiseration when watching or experiencing physical, or psychological pain being inflicted.

Using “I felt that one!” In a conversation:

Husband: Do you want to watch some couples porn or a tennis match?

Wife: Let’s watch the couples porn; you can play tennis pretty well.

Husband: Ouch! I felt that one!

I felt that one! by Mind Hunter the Profiler February 18, 2023

That one Nagito edit

That one Nagito edit is a video made by a YouTuber named Blue Akrasia, a YouTuber who has made multiple 30-second edits of characters from many different animes and games. They've made multiple edits of danganronpa characters, but none have been as known as this Nagito edit. It uses a Gorillaz song called "Rhinestone Eyes", and is really good. It has over 1 million views on YouTube, and even more on TikTok. Multiple recreations of this edit with different characters have been made. This edit got very popular mostly likely due to the recreations and loops made of the video. Luck was also of course part of it getting popular.

Person 1: Hey have you heard of that one Nagito edit?
Person 2: The one with that "Rhinestone Eyes" song?
Person 1: Yep!
Person 2: Of course I've heard of it! It's everywhere!

That one Nagito edit by LucinaLowellisnotok November 19, 2020

That One Gay Cousin 

That One Gay Cousin is well, your gay cousin. If you don't have one, chances are, YOU ARE that one gay cousin!

Person 1: Who is your one gay cousin?
Person 2: I don't have a gay- oh shi- I guess I'm the gay cousin...
Person 1: Congrats! I always knew you were that one gay cousin!

That One Gay Cousin by IHateNamingThings.org April 6, 2019

that one time 

...you know, when you did that that one thing.

James: "Remember that one time?"
Robert: "You mean when we did that one thing?"
James: "Yeah!"

that one time by TheGrainmaker February 12, 2009