underdevelopsy 

Lackage of the package.

My younger brother suffered with underdevelopsy for most of his teen years

underdevelopsy by GirthDoctor January 9, 2020

a horrible pixelated shot of an underdeveloped highschool freshman in their underwear trying their best to make a seductive face 

The default picture used by over 84% of users of the popular networking site myspace (See definition #4).

-Man, she looks fine!
-Can't you tell? That's a horrible pixelated shot of an underdeveloped highschool freshman in their underwear trying their best to make a seductive face, dude.

a horrible pixelated shot of an underdeveloped highschool freshman in their underwear trying their best to make a seductive face by cchriss92 August 9, 2007

IQ Underdevelopment 

When your IQ is apparently 'lower than current age standards' of your peers in your age group.
In short, nonsense about your IQ and how dumb you are.

Me : "According to my test IQ results, I have 'IQ underdevelopment'."
Human 2 : "Now, why isn't that surprising mate "
Me : F*** you !

IQ Underdevelopment by Cloudyshadow October 31, 2017