The act of compressing the breasts to the point of flatness. Either knowingly or unknowingly. The act is usually performed by wearing a sports bras at all times; even when not engaging in physical activity. It is speculated that pankaking can lead to saggy tits in later life.
1. An ancient American ritual where a party of 8 or more men ejaculate on a pancake. This is sometimes done if the pancake has commited a crime or disrespected the elders in any way, but mostly it's done for entertainment at bachelor parties.