The lowest level of bribery, generally associated with breaking the law i.e. dirty cop/agent/attourney. This could be as simple as taking free food and coffee from local eateries and turning a blind eye to there less than stellar activities or keeping confiscated goods without raising any flags or perpatrating the offenders.
Referred to by this name because the parties invovled are not making significant exchanges of worth but more like grazing off the top.
Chubbs has been grass eating for years, it was only a matter of time before he got on Noreaga's take.
cop1: "You need to cut that grass eating shit out Pat, you are going to get the whole force in some shit."
cop2: "Relax, no one is going to miss one zipper when we turn in the two kilos..."