A rack or frame on which relays are mounted; (in later use) a standardized metal rack designed to hold panels nineteen inches in width on which amplifiers, equipment for computer servers, or other electronic modules can be mounted.
Origin
Early 20th century; earliest use found in American Telephone Journal.
Definition of relay rack in US English:
relay rack
noun
Electronics
A rack or frame on which relays are mounted; (in later use) a standardized metal rack designed to hold panels nineteen inches in width on which amplifiers, equipment for computer servers, or other electronic modules can be mounted.
Origin
Early 20th century; earliest use found in American Telephone Journal.