cardslot 

an extreme variation of the "coinslot", where a girl's pants ride so low that the amount of ass crack showing more closely resembles something into which one would jam a debit card.

Check out that skank's cardslot! Hey! Turn around, bitch! I need to make a withdrawal!

cardslot by beansoup July 31, 2011

Credit Card Slot 

A human female Vagina

Her credit card slot was so tight

Credit Card Slot by Mosher kid February 6, 2021

Credit card slot 

The fat roll(s) in the back of the head.

That guy has a deep credit card slot.

Credit card slot by RozaBelikova November 16, 2022