You're just waiting until he's six feet under so you can get your hands on his money.
idiombe six feet underdead a humorous expression used about someone who is dead:Well, your 40th birthday party won't be my problem - I'll be six feet under by then.
be six feet under
slang To be dead. This phrase alludes to one having been buried underground. I'll be six feet under long before taxes in our city go down.You'll be six feet under when mom finds out that you dented her brand-new car.