An insult generally directed at people younger than you, like a brother or sister, or that stupid kid down the street. An ideal "Dirty Schroder" has one or more of the following characteristics:
Fat
Trashy
Smelly
Bitchy
11-14 years of age
Person who won't leave you (or your stuff) alone
**Note that once you are a Dirty Schroder, you will always be one, regardless of your current characteristics**
"Dirty Schroder" is also synonymous with "Dirty Cock'm"