Definition: - Adjective: "Downhill" describes something that is sloping down, usually steeply. For example, if you are walking or skiing, and you are going down a hill, you are going downhill.
As an Adjective: Use "downhill" to describe something that is sloping down.
As an Adverb: Use it when describing movement towards a lower place.
As a Noun: Use it when talking about skiing or the slope itself.
"Going downhill": This idiom means that something is getting worse or declining.
"Downhill from here": This phrase means that after a certain point, things will become easier or better.