mainframe
n. C1 Advanced US //ˈmeɪnˌfɹeɪm// UK //mˈeɪnfɹeɪm// main·frame
n. a very large and powerful computer used by big companies or governments to handle huge amounts of data.
n. a high-performance computer system designed for high-volume data processing and critical applications requiring extreme reliability.
The bank uses a mainframe to process millions of transactions every day.
While many companies have moved to the cloud, some still rely on a central mainframe for their most sensitive financial records.
The transition from legacy mainframe architecture to distributed cloud systems remains a significant technical challenge for many established government agencies.
From main + frame.
Usage
Often used as a modifier before other nouns, such as 'mainframe computer' or 'mainframe system'.