Synonyms for grinding include the figurative terms "treadmilling" (a comparison with exercise treadmills) and "pushing the bar" (it can be a reference to a weightlifter "pushing the bar" on a bench press, over and over to get muscle gains, or a reference to Skinner boxes in which animals, having learned that pushing a button will sometimes produce a treat, will devote time to pushing the bar over and over again , or also can be a graphical reference to "push" the character's experience bar to higher values). Related terms include "farming" (in which the repetition is undertaken in order to obtain items, relating the activity to tending a farm field), and "catassing", which refers to extended or obsessive play sessions. Used as a noun, a grind (or treadmill) is a designed in-game aspect which requires the player to engage in grinding.