Countdown Girl 

Countdown Girl - A female that looks good from a distance, but her appearance becomes progressively worse upon approach.

"I thought she was hot, but she ended up being a Countdown Girl."

"What do you mean a countdown girl?"

"I thought she was a 10, but as I was walking up to her she turned into a 9...8...7...6..."

*Hysterical Laughter*

Countdown Girl by Dee Wayne December 7, 2009

Countdown Girl 

An attractive female who studies maths or has a degree in it.

However it can generally be used to describe any attractive and intelligent girl.

"Brooo, you see that fit girl walk out of science class?" Damn she's a proper countdown girl"

Countdown Girl by shitsplatter September 21, 2013

countdown girl 

A person that every time you see them their Hotness level drops, beer or any other such judgment imparting drink or substances not involved

Dude, she is a countdown girl, yesterday she was a 10 and today shes a 9, who knows how far she will fall.

countdown girl by CisforCookie January 3, 2008