substation

noun4

1. •
   Any subordinate station.
2. •
   A site where electricity supplied by long-distance (high-voltage) transmission lines is transformed or regulated for local (low-voltage) distribution.

   • The utility now wants the network to be undergrounded in the urban areas, which would mean substations with 33 kV distribution swtichgear. — 2006
3. •
   A satellite police station serving one neighborhood or part of a larger jurisdiction.
4. •
   A branch post office.