undefined is just what it says
That is undefined to the MAX

by stav August 10, 2004
Undefined behavior results when programs attempt to do things for which the standard defines no semantics, and requires no diagnostic either. Examples include dereferencing invalid pointers and dividing by zero. Executing such programs may cause them to produce incorrect results, crash, silently "work", or even format the hard drive.
It is commonly joked that undefined behavior allows the compiler to insert code that will start a game of nethack.
by henke37 May 23, 2014
A word that hasn't been defined yet on Urban Dictionary. These are EXTREMELY rare, as someone has either stole your idea, or you aren't creative enough.
Horny Teen 1: What are you doing?
Horny Teen 2: Trying to find an undefined word in the good ol' UD.
Horny Teen 1: Why?
Horny Teen 2: So I can define it, idiot!
by RedRabbit1987 March 19, 2019
One who utilises UrbanDictionary.com as a message board, writing and responding to other users rather than actually writing any type of definition (silly or otherwise) of a word or term.
'The last definition said something about people never getting this word right. Well, I think that when some--'

'Just stop, Jesse. Do not join the urbandicks by playing that "urban undefiner" game.'
by Kyle Lees April 22, 2006
1. The idea of having a social life does not exist in the person's mind. Where the idea of having friends, the concern of not having friends and dating is inconceivable and is of not existence. The reason being is that person has never been predisposed to it in the first place, so the idea of not having friends does not bother him or her. In other words, take for example the Sims computer game. It's like having a sim that has no social bar on the needs indicator. By having an undefined social life, the person does not have to worry about maintaining friendships, giving gifts, working out relationships,losing, nor betraying friends. Because the person who has and undefined social life has nothing to lose. It's like dividing a number by zero when it comes to determining the number of friends an undefined social life person has.
John has never had friends; he does everything by himself. He must have an undefined social life because he is always happy doing things by himself. Whenever someone asks John if he has ever had a girlfriend, he just looks at them weird at complete and utter confusion.
by AJHM May 18, 2007
An interjection of disgust about something that will never work from recently on, no matter how hard or easy you try. Usually it's an item or idea that has worked well in the past, but is totally knackered in this modern age. Comes from C programs written for an older version of the toolchain which flatly refuses to compile on the newer toolchain.
Going to war with spears?? Undefined reference to _sbrk!

I tried to use sorcery to turn my Yugo into a Rolls Royce, but got an undefined reference to _sbrk.

CoolGBARom.c error: undefined reference to _sbrk