A silk skin is when you hide your lunch money in your sock to avoid it being stolen from bigger kids. Its origin comes from slang used by smaller kids who often have their lunch money stolen.
Oh, I thought I lost my lunch money, but I was just (whisper) "silk skining".
The Urban Dictionary Mug
One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.
Buy the mug