# What is the meaning of “steep horizontal pressure gradient”?

I could not solve the meaning of steep in this phrase:

Could you paraphrase the sentence or give me the synonym of this word meaning in this sentence?

"Horizontal pressure gradient" is a technical term.

According to Wikipedia, "The horizontal pressure gradient is a 2-dimensional vector resulting from the projection of the pressure gradient onto a local horizontal plane."

When we say "steep horizontal pressure gradient", we simply mean that it's strong. For example,

HORIZONTAL PRESSURE GRADIENT.— The horizontal pressure gradient is steep or strong when the isobars determining the pressure system (fig. 3-7) are close together. It is flat or weak when the isobars are far apart.
Source: http://meteorologytraining.tpub.com/14312/css/14312_65.htm

Presumably, pressure is indicated on the horizontal or x-axis.
Steepness is defined by how quickly it changes per unit moving along the x-axis.

In the graph, substitute Pressure" for "Distance".

(source: tulane.edu)