A prop or support (to prevent s.t. from falling over).
It may be wood or stone of any size.
Fetch us a prop for propping up this tree so that it won’t fall.
This wood I will use as a support for my house.
To support s.t. (with a prop of wood or stone); to prop up s.t.
The house is propped up because it is about to topple.
They are propping up a tree because it is about to fall.
I am off to prop up my banana plant.
If you have work to do do not prop your knee up under (on) your chin. It is shameful because it is a sign of a lazy person.