Rimming or Anal Rimming means “the act of using one’s tongue on the anal rim of another person in order to gain and/or give sexual pleasure.”

Rimming, tossing the salad, analingus. You've heard the terms, but how do you do it? Learn how to eat the booty like a pro! Check out this great article Emily Anne wrote on how to rim http://sexwithemily.com/rimming-beginners-guide/

Urban Dictionary: rimming The act of using one's tongue on the anal rim of another person in order to gain and/or give sexual pleasure. Insertion of the tongue is not necessary. Circular motions in the clockwise directions are supposedly better in the Northern hemisphere, and anti-clockwise ones in the Southern.