“Steep” you may know as in a steep hill (una colina empinada). Tenerife has many of them. “Teide” rises steeply (Teide está cortada a pico).
“Steep” can also mean “abrupto” o “pronunciado”. Here is an example: there has been a steep drop in unemployment in Spain. Or, there has been a steep rise in the number of employed people in Spain.
There are other uses. If someone makes an unreasonable demand we say “that is steep” (eso es demasiado). Here steep is an adjective. You may consider that the cost of a Porsche at 100,000 euros is “steep” (¡que caro!).
You can say that La Laguna, the city, is “steeped” in history (una cuidad impregnada de historia o una cuidad de gran riqueza histórica). A ceremony can also be steeped in ancient traditions.
The adverb is “steeply”. Here is an example: under some governments taxes rise steeply (marcadamente o se dispararon).
So we have steep hills and mountains, steep rises in the cost of things or taxes, steep falls in unemployment, and when something is unreasonable, you can that it is “steep”.