1) When the bowl has been smoked and nothing remains but ash.
2) Also used as slang for when anything is empty. Derived from when a casino is out of money.

"This bowl is cashed, let's smoke another".
"This bag of chips is cashed, let's go get more".
by Luna29 on 07/25/2017

When it ain’t nothing but ash. If you hit it again the remains are going to get all in the bong.

“Let me tap this bowl out in the ashtray before you put more weed in, it’s cashed as fuck.”
by Ashley on 04/16/2018