retrofit
n.n. a new piece of software or hardware that you add to an old system to make it work better or do something new.
n. a modification or addition to an existing system to improve its functionality or performance. Often refers to software updates or hardware components added to legacy equipment.
The company installed a retrofit to make the old machines more energy efficient.
The city council approved a retrofit for the historic library to install modern climate control systems without damaging the original architecture.
While the original hardware was designed for a specific protocol, the retrofit allows it to communicate seamlessly with the latest network standards, extending its operational life by several decades.
The verb is derived from retro- (prefix meaning ‘back; backward’) + fit (“to equip, supply”). The noun, which is first attested later than the verb, is either derived: * from the verb (see above); or * from retro- + fit (“act of fitting; conformity of elements one to another”).