step-down

from WordNet (r) 3.0 (2006)

step-down
    n 1: the act of decreasing or reducing something [syn:
         {decrease}, {diminution}, {reduction}, {step-down}] [ant:
         {increase}, {step-up}]

from The Collaborative International Dictionary of English v.0.48

Step-down \Step"-down`\, a. (Elec.)
   Transforming or converting a current of high potential or
   voltage into one of low voltage; as, a step-down transformer.
   [Webster 1913 Suppl.]