down·hill /ˌdaʊnˈhɪl/
 (a.)(ad.)下坡的,衰退的,走下坡路的
 Down·hill adv. Towards the bottom of a hill; as, water runs downhill.
 Down·hill, a. Declivous; descending; sloping. “A downhill greensward.”
 Down·hill, n. Declivity; descent; slope.
    On th' icy downhills of this slippery life.   --Du Bartas (Trans. ).
 ◄ ►
 downhill
      adj : sloping down rather steeply [syn: declivitous, downward-sloping]
      n 1: the downward slope of a hill
      2: a ski race down a trail
      adv 1: toward a lower or inferior state; "your performance has been
             going downhill for a long time now"
      2: toward the bottom of a hill; "running downhill, he gained a
         lot of speed"