noun (n)

• a large digital computer serving 100-400 users and occupying a special air-conditioned room(noun.artifact)

  Synonym:
  mainframe computer
  

  source: wordnet30
• (computer science) the part of a computer (a microprocessor chip) that does most of the data processing(noun.artifact)

  Synonym:
  c.p.u., central processing unit, central processor, cpu, processor
  

  source: wordnet30