1. [ noun ] (geography) the downward slope of a hill
Related terms: descent
2. [ adjective ] sloping down rather steeply
Synonyms: downward-sloping declivitous
Related terms: descending
3. [ adverb ] toward the bottom of a hill

"running downhill, he gained a lot of speed"

4. [ adverb ] toward a lower or inferior state

"your performance has been going downhill for a long time now"

5. [ noun ] (sport) a ski race down a trail
Related terms: ski_race
Similar spelling:   Donella