Foothill (noun): A relatively low hill found at the base of a mountain. Foothills are usually smaller than mountains and are often part of a larger mountain range.
In more advanced contexts, "foothills" can refer to the region itself where these hills are located, often used in discussions about ecosystems, climate, or outdoor activities.
While "foothill" primarily refers to geographical features, metaphorically, it can describe a preliminary step or early stage in a process, similar to the way a foothill is the first step toward a mountain.
There are no specific idioms or phrasal verbs that directly use the word "foothill." However, you might encounter phrases like "the foothills of success," meaning the beginning stages of achieving something significant.
So, remember that a "foothill" is a low hill at the base of a mountain.