To give/recieve the:
1. A clumsily placed dirty sanchez.
2. An act of unsolicited anal penatration which would cause the recieving party to frown.
1. "... found out the bitch had been cheating on me so I gave her the Brown Frown before kicking her out of my house!"
2. "... I dropped the soap and went to pick it up, then all of a sudden I was in terible agony as I found myself on the recieving end of a Brown Frown!"