Can be any piece of cloth that is used to pick up the remnants of 300 million potential children. Every teenaged boy owns at least one and it can be found near his computer or bed. Usually a white shirt that is worn under the main shirt.
Usually white in color. If you or a loved one uses any other color, you are unashamed to show everyone what you do when you're alone or your man juice is colored differently, in which cases, you're either going to need to get checked for STD's or see a psychiatrist.
The shirt that you reluctantly wear because you forgot to put your laundry in the dryer.
The family member of friend that you reluctantly look at because he/ she borrowed THE shirt and is wearing it.
The shirt you wore to Thursday's Black Light Bowling Night and everyone mistook you for a sperm bank.