Based on the words cash and hashish, the term was coined by a bearded weed-fiend and originally used to describe money set aside to buy hash but usage has widened to describe money set aside to be later invested in non-specific recreational or social activities.
Any cashish you make on the deal you can bring and buy us beverages
1) A great deal of cash 2) Cash referenced as if it were as powerful as a drug
1) Max: "Are you going to work on Saturday?"
Scott: "Of course dude, there is a serious amount of cashish to be made with overtime!!"
2) Max: "I need some cashish to buy the wife her new boob job."
Scott: "Is that REALLY necessary, I mean is she that materialistic that she needs balloons in her chest?"
Max: "Yes, and so am I!"
Scott: "Excellent"