1.(noun)The phrase "A bag of day old dicks" is used to describe someone who has been a bag of dicks for so long that they are outdated, or tend to smell. The phrase can also be used to desribe a topic that has been used and abused for so long that no one wants to hear it any longer.
2. The phrase can also be used to describe something that smells because it is rotten or just disqusting.
That group of gutter punks on the corner just smelled like a bag of day old dicks when we walked by.
Yesterday we talked about bags of dicks for 12 hours straight until the bag of dicks grew to be a bag of day old dicks.