retrofit

(noun) a component or accessory added to something after it has been manufactured.

(noun) the act of adding a component or accessory to something that did not have it when it was manufactured. Example: "The court ordered a retrofit on all automobiles."

(verb) provide with parts, devices, or equipment not available or in use at the time of the original manufacture. Example: "They car companies retrofitted all the old models with new carburetors."

(verb) fit in or on an existing structure, such as an older house. Example: "The mansion was retrofitted with modern plumbing."

(verb) substitute new or modernized parts or equipment for older ones. Example: "The laboratory retrofitted to meet the safety codes."