Definition of an activity that can only be played indoors such as Fortnite or League of legends, which are clearly a total waste of ones life
“Your insideness is ruining your life - get off the Fortnite, out of the house and do something useful”
by rusty3105 December 26, 2019

"Oh, look Jhon, they wrote John on the bowling alley screen, now I will occasionally call you John pronounced JO-HNNNN, forever on, this will be an inside joke!"
by reallyunfunnyguy December 7, 2023

by Dream_69 October 16, 2021

by TheAssEater2000 May 17, 2016

by AnyaForger May 8, 2022

The thing that Urban Dictionary hates and will not let you publish a definition if it includes an inside joke
by nabrU yranoitciD January 13, 2020

A word or term submitted by people on Urban Dictionary that usually revolves around a person or thing that very few people other than the submitter actually know about, with said word or term often having a definition that does not accurately or effectively explain what it actually is to people who have never heard of such a thing before
by Unrealistic Trap-like Pervboi February 1, 2018
