1. cooling system a mechanism for keeping something cool
  2. coolant system a cooling system that uses a fluid to transfer heat from one place to another
  3. coding system a system of signals used to represent letters or numbers in transmitting messages
  4. filing system a system of classifying into files
  5. scoring system a system of classifying according to quality or merit or amount
  6. gambling system a system of rules for placing bets that is believed to lead to winning
  7. voting system a legal system for making democratic choices
  8. writing system a method of representing the sounds of a language by written or printed symbols
  9. heating system utility to warm a building
  10. rating system a system of classifying according to quality or merit or amount
  11. recording system audio system for recoding sound
  12. computing system a system of one or more computers and associated software with common storage
  13. accounting system a bookkeeper's chronological list of related debits and credits of a business; forms part of a ledger of accounts
  14. ecosystem organisms interacting with their physical environment
  15. banking system banks collectively
  16. coordinate system a system that uses coordinates to establish position
  17. lens system a transparent optical device used to converge or diverge transmitted light and to form images
  18. drainage system a system of watercourses or drains for carrying off excess water
  19. pricing system a system for setting prices on goods or services
  20. plumbing system utility consisting of the pipes and fixtures for the distribution of water or gas in a building and for the disposal of sewage