In the most general sense, anything crustless is the outcome of an intensified suburban culture. The term "crustless" itself refers to the act of cutting crust off of a sandwich in order to make it more palatable for a crustless child. But the sandwiches are just the beginning. Being crustless is a lifestyle, not just a way to eat...see thecrustless.blogspot.com for good examples
"Did you see that kid's zip-off pants? Those are so crustless!"
Any sock with length below the ankle. Such as low cut socks and slip-on socks.
Person A: Hey, I can’t seem to find my crustless socks
Person B: Your what?
Person A: Bruh my slip-on socks