The sexual practice of inserting objects into a vagina or anus that are significantly larger than the orifice's typical circumference, causing pleasurable stretching.
When your in a car on the highway with a group of friends, the driver puts his signal on and lets go of the wheel with his foot on the gas, every person in the car crams to one side of the car to shake it and cause the car to switch lanes.
The act of forcing every last inch of your dick inside a girl's pussy. When you feel your balls press against her soft pussy lips you have successfully crammed her. Also known as going balls deep.