adj .
steep 가파른, 경사가 급한

• Precipitous means like a precipice, or cliff. It and precipitate are very closely related, as you probably guessed. But they don't mean the same thing, even thought precipitous is often used loosely to mean the same thing as precipitate.
• A mountain can be precipitous, meaning either that it is steep or that it comprises lost of steep cliffs.
• Precipitous can also be used to signify things that are only figuratively steep. For example, you could say that someone had stumbled down a precipitous slope into drug addiction.