From Longman Dictionary of Contemporary Englishdownhilldown‧hill1 /ˌdaʊnˈhɪl◂/ adverb 1 BOTTOMtowards the bottom of a hill or towards lower land OPP uphill I was going downhill and my brakes failed.2 → go downhill
Examples from the Corpus
downhill• You feel the situation is going downhill.• I awoke in pain, still hung over from the Nembles, and from there I proceeded to stumble downhill.• Nora guessed that if there was a fox in there and if it broke, it would seek first to go downhill.• The wind was strong from them to me so eventually they would scent me when they'd passed downhill.• After we get to the top it'll be downhill all the way to Kendal.• It was downhill in top gear now.• The truck rolled downhill into a parked car.• They have different styles: Warren runs downhill, looking to make cuts, while Broussard is more explosive.• The men had been in unknown country, chasing the boar uphill, when the rule is to chase downhill only.• We set off downhill towards the lake.downhilldownhill2 adjective 1 HORIZONTALon a slope that goes down to a lower point OPP uphill downhill skiing It’s a long walk back, but at least it’s all downhill.2 → be all downhill (from here)/be downhill all the way (from here)Examples from the Corpus
downhill• Since the Second World War it has all been downhill.• When she arrived at the edge of the covert, she made her way cautiously along its downhill fringes.• The third was a downhill par-four of 286 yards on which par was an exceptionally pleasing score.• He grabbed one out of my hand and lined up a tough 10-foot downhill putt.• I faced an uphill challenge with a downhill set of assets.• But somewhere along the line, downhill skiing was too much of a chore and an expense.• a downhill slideFrom Longman Business Dictionarydownhilldown‧hill /ˌdaʊnˈhɪl/ adverb if something that was successful is going downhill, it is starting to fail, and is getting gradually worseSales had peaked in 2005 at $3.8 million but had gone steadily downhill. 