Mainframe
WordNet
noun
(1) (computer science) the part of a computer (a microprocessor chip) that does most of the data processing
"The CPU and the memory form the central part of a computer to which the peripherals are attached"
(2) A large digital computer serving 100-400 users and occupying a special air-conditioned room
WiktionaryText
Noun
- A large, powerful computer able to manage very many simultaneous tasks and communicate with very many connected terminals; used by large, complex organizations (such as banks and supermarkets) where continuously sustained operation is vital