The act of farming.
Farming is the act of repetively killing a mob for the express purpose of gathering items that they drop. It is very similar to Grinding in many way, since in most case, when you're grinding, you are also farming mobs.
Also the act of repetitively traveling the same route (e.g. flying in circles around the borders of Sholazar Basin) for the purpose of getting as many nodes (herbs, mines, etc.) as possible. Not generally questing or doing anything else while doing this, just gathering as many raw materials as possible for crafting or for sale on the auction house.