Jackowell 

To have sexual intercourse with your ex’s cousin

Jackson: “Dude me and Leah’s cousin Maren totally banged last night”
Vinnie: “Bro you are such a jackowell”

Jackowell by thedictionaire47 February 23, 2025

Jacobellis

To embarassingly sabatoge one's own chance at success moments before acheivement by becoming overly confident and showing off. Derived from U.S. snowboarder Lindsay Jacobellis' tumble at the 2006 Olympics.

Jimmy pulled a major Jacobellis the other day. He was almost at the finish line for the 400 meter, then he started dancing, and tripped. The other runners stepped on him, and he came in last. Poor Jimmy.

Jacobellis by WestCoastLisa March 1, 2006

Jacknjellify

jacknjellify is a YouTube account owned by Michael and Cary Huang, who host Battle for BFB (BFB). They are known for their marble races and their BFDI series. The account was founded on February 4, 2008, making animations and marble races. The first episode of BFDI was released on January 1, 2010 and their channel has been running for over ten years. jacknjellify also makes other animations, but BFDI is their main project. Many individuals refuse to watch the series properly, they therefore judge it and the fanbase after watching 6 seconds of the oldest episode.

Someone literally getting crushed to death by their giant ego: "Jacknjellify is dumb because it makes Tiktoks, hurr hurr I'm a stupid reddit cuckhead, funny 69 number is funny.".
An intellectual: "No it's not retard, hundreds of youtube channels (especially those that focus on animation as their primary content) make tiktok accounts in order to sustain popularity between upload, you inchoherent bag of total horse shit".

Jacknjellify by AFUNCTIONALMEMBEROFSOCIETY March 8, 2021

Jacobellis

Pronunciation: JAKE-uh-BELL-is

Function: Verb

Dates: 2006, 2010

1. To cost oneself athletic glory and sentence oneself to a lifetime of smarmy people using surname as a verb, esp. through youthfully hubristic hot-dogging.

2. To spin out and end an Olympic Games in disappointment.

Synonyms: Van de Velde.

duh............ not again................ you Jacobellis....................

Jacobellis by XR4ti February 17, 2010

Jacobellis

Deservedly losing a competition by showing off before actually completing the race.

He was way in front of me by a mile and a half, then I got lucky when he pulled off a Jacobellis.

Jacobellis by Jiufu August 28, 2008

jackwilliam 

A guy who doesn't have friends but also gets girls because they think he's gay

"Bro why does Jackwilliam get SOO many bitches"
"It's cause they think he's gay"

jackwilliam by UnknownGuy555 June 23, 2017

jacobellis

(Verb) To lose in the face of certain victory because you were showing off.

"He could have had a promotion too, but he really jacobellised when his boss caught him bragging about his raise."

jacobellis by New York Tootie July 31, 2008