look up any word, like blumpkin:
 
1.
More formally know as a cock block. Dirty C is the act of interrupting a bro getting his dick wet multiple drunken times in one night. Once a person has preformed the Dirty C they will never return the status of a bro. A Dirty C is not liked by anyone but is a commonly reoccurring factor that is taking America by storm.
Thomas: "I was having a great time last night until Matthias walked in to the room."

Arthur: "I can't believe he pulled another Dirty C"
by MeowKitten May 06, 2012