undecider 

a person who is chronically unable to reach a fast decision, no matter how mundane that decision is

"Bringing the undecider to the pumpkin patch may have been a mistake. We're going to be here all day."

undecider by anemeth October 8, 2011

Undecided Voters

The 2nd-biggest idiots on the planet, right behind people who vote solely because of party.

Those clueless undecided voters are almost as stupid as Bob, who voted for George W. Bush just because he was a Republican!

Undecided Voters by don'tuseurrealname February 12, 2013

undecided 

to be super high

woah, that was enough marijuana. im reallyyy undecided right now!

undecided by super tokie June 21, 2009

Undecided 

A person either a guy or a girl who isn't quite sure of their sexuality yet.

It's a phase that everyone goes through in some point of their life.

-What's with tony posting all these pictures of hot guys on Damien and Sophie's wall? I thought he was straight?

- Tony? yeh, no he's actually undecided

Undecided by Livinglifebytheseconds September 22, 2010

undecimber 

an extra month on the calender instead of the usual 12 months.
if there was a 14th month then it will be called Duodecimber or Duodecember.
there was a 13th month, the govenors has just been hiding them from us this entire time.

Everyone: WOOOOOO FUCK 2020 2021 HERE WE GO
13/1/2020 12:00:00 AM
Everyone: wait, its Undecimber 1, 2020?
Govenors: always has been.
Some random guy: WOOOOO UNDECIMBER 1 EXTRA MONTH OF 2020 HERE WE GO

undecimber by IAmCassal December 30, 2020

Undecidatard 

A person unable to make a decision.

I coudn't come to a decision for anything, despite only having to decide what menu item to choose, I'm being an undecidatard.

Undecidatard by behooved December 24, 2009

urban undefiner 

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.'

urban undefiner by Kyle Lees May 3, 2006