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

by IAmCassal December 30, 2020

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."

by anemeth October 8, 2011

Undecember

The month between December and January in which the holiday spirit is worn off and all decorations are taken down.

The Grinch's favorite month is Undecember.

by #+_+# December 6, 2025