Put on the wooden overcoat old-fashioned slang
Wooden overcoat alludes the coffin.
When you say someone puts on the wooden overcoat, you mean that they die or pass away.
You should adopt a healthier lifestyle, if you don't want to put on the wooden overcoat soon.
He put on wooden overcoat in a car crash last night.
To die or pass away
1. To pass away
2. To depart suddenly
1. One's success has gone down or ended.
2. One has passed away.
To die
The verb "put" must be conjugated according its tense
The origin of this idiom isn't clear. It seems to be of American origin, since the majority of the earliest written citations are from the United States.