The scariest thing is usually the thing that you are afraid of the most. When you are asked to name the scariest thing, you might choose something that you are already afraid of, or you might choose something that you haven't experienced yet.
To stagnate is to stop growing or to decline in quality. When the economy starts to stagnate, the number of jobs and the amount of money that is being spent are both going down.
To plummet is to fall rapidly and suddenly. When the stock prices fell, the market plummeted.
To plummet is to fall quickly and suddenly. When the stock market crashed, the prices of all the stocks fell very quickly.
To prop something is to support it with something. You might prop a door open with a stick so that the wind can't close it.
Repairable means that something is able to be fixed or rebuilt. This can be a good thing, because it means that something can be fixed or improved.
Weaponized means that something has been turned into a weapon. When a country starts to weaponize its nuclear capabilities, it means that it is planning to use its nuclear weapons.
An autocrat is a ruler or leader who is not elected by the people. They usually have very little freedom, and they are usually not allowed to criticize the government or their leaders.
Dooming is a verb meaning to declare or to predict that someone or something is going to fail or be unsuccessful.