retrofit

American  

[re-troh-fit, re-troh-fit, re-troh-fit] / ˈrɛ troʊˌfɪt, ˌrɛ troʊˈfɪt, ˈrɛ troʊˌfɪt /

verb (used with object)

• retrofits,
  present (3rd person singular)
• retrofitted,
  past participle,  past
• retrofit,
  past participle,  past
• retrofitting
  present participle

1. to modify equipment (in airplanes, automobiles, a factory, etc.) that is already in service using parts developed or made available after the time of original manufacture.

2. to install, fit, or adapt (a device or system) for use with something older.

   to retrofit solar heating to a poorly insulated house.

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verb (used without object)

• retrofits,
  present (3rd person singular)
• retrofitted,
  past participle,  past
• retrofit,
  past participle,  past
• retrofitting
  present participle

1. (of new or modified parts, equipment, etc.) to fit into or onto existing equipment.

2. to replace existing parts, equipment, etc., with updated parts or systems.

noun

• retrofits
  plural

1. something that has been retrofitted.

2. an instance of updating, enlarging, etc., with new or modified equipment.

   A retrofit could save thousands of dollars.

adjective

1. being or characterized by a retrofit.

   retrofit units.

retrofit British  

/ ˈrɛtrəʊˌfɪt /

verb

1. (tr) to equip (a vehicle, piece of equipment, etc) with new parts, safety devices, etc, after manufacture

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Other Word Forms

Derived Forms

• retrofittable
  adjective

Inflected Forms

Nouns

• retrofits
  plural

Participles

• retrofitting
  present
• retrofit
  past
• retrofitted
  past

Conjugated Forms

Present

• retrofit
  simple
• retrofits
  simple
• have retrofit
  perfect
• have retrofitted
  perfect
• has retrofit
  perfect
• has retrofitted
  perfect
• am retrofitting
  progressive
• are retrofitting
  progressive
• is retrofitting
  progressive
• have been retrofitting
  perfect progressive
• has been retrofitting
  perfect progressive

Past

• retrofit
  simple
• retrofitted
  simple
• had retrofit
  perfect
• had retrofitted
  perfect
• was retrofitting
  progressive
• were retrofitting
  progressive
• had been retrofitting
  perfect progressive

Future

• will retrofit
  simple
• will have retrofit
  perfect
• will have retrofitted
  perfect
• will be retrofitting
  progressive
• will have been retrofitting
  perfect progressive

Etymology

Origin of retrofit

retro- + fit ¹

Explanation

When you retrofit something, you replace old parts with new ones. You might retrofit an antique car with updated brakes and seat belts, for example. You can use retrofit as a verb, or it can be a noun meaning the new part itself, or something that's added on later. The solar panels on your two hundred year old house are a retrofit, and so is the fancy new stereo in your beat up old car. Retrofit has been around since the mid-1950s, when retroactive and refit were combined into a new word.

Example Sentences

See Examples For:

retrofit retrofits retrofitted retrofitting

Leaders must scramble to retrofit workplaces like hospitals and schools with air conditioning, support farmers switching crops, and build out irrigation systems and water reservoirs.

From The Wall Street Journal ● Aug. 31, 2026

Ortberg said Boeing is using a “side shop,” a factory where retrofit work for those older 777 airframes could be done without interrupting production of new jets.

From The Wall Street Journal ● Jul. 21, 2026

California residents can prepare for an earthquake in a number of ways including property owners assessing whether a retrofit is needed, even if it isn’t required by a city ordinance.

From Los Angeles Times ● Jun. 25, 2026

The alternative to this is to build new bespoke plants or retrofit existing facilities with new kit, from companies like Colorado-based AMP.

From BBC ● May 4, 2026

The Center has since benefitted by a forty-million-dollar retrofit, but there's still enough forest and swamp on the facility for the Border Patrol to put in tracking practice.

From The Hacker Crackdown, law and disorder on the electronic frontier by Bruce Sterling

Nearly 50% of Nuveen Green Capital’s deployment activity is focused on new construction, with the rest being allocated to building retrofits for things like solar energy upgrades.

From The Wall Street Journal ● Aug. 25, 2026

American Airlines expects screens to be installed across its full fleet by early in the next decade, with retrofits starting in 2028.

From The Wall Street Journal ● Aug. 18, 2026

On Net Zero he proposes a "Northern Way", which subsidises the transition, retrofits, cutting bills, and building exportable locally owned industry.

From BBC ● Jul. 17, 2026

While some local governments across California have required retrofits of older, seismically risky buildings, many others have not.

From Los Angeles Times ● Oct. 16, 2025

In South Pasadena, with a population of 26,000, building official Dennis Tarango said the city has no plans to create an inventory of soft-story apartment buildings or consider mandatory retrofits.

From Los Angeles Times ● Nov. 23, 2024

They lived in makeshift apartments and partied in retrofitted warehouses.

From Salon ● Aug. 30, 2026

One of Parton’s first forays into purer pop, this single has the stomp and shuffle of funk and could easily be retrofitted into disco DJ sets.

From Los Angeles Times ● Aug. 25, 2026

For excursions on land, Green Safaris’s lodges have retrofitted Land Rovers to run on batteries.

From The Wall Street Journal ● Aug. 16, 2026

A vehicle was retrofitted so that Lillard could drive.

From BBC ● Jul. 14, 2026

Sing Sing, for reasons no one could ever explain to me, has never been retrofitted with gas.

From "Newjack: Guarding Sing Sing" by Ted Conover

But the Passivhaus Trust - for which Baeli is a non-executive director - acknowledges retrofitting your home to this standard is "expensive".

From BBC ● Aug. 21, 2026

One study, published in 2020, discussed how experts might recommend retrofitting riskier buildings.

From Los Angeles Times ● Jun. 25, 2026

At those levels, buyers can commission their own dream homes instead of retrofitting someone else’s fantasy.

From MarketWatch ● Jun. 3, 2026

The Senate’s mandate would generally be more prescriptive on retrofitting aircraft, while the House’s version would allow more flexibility in how to comply.

From The Wall Street Journal ● May 31, 2026

In April the government approved a legal framework to allow people to convert their petrol and diesel vehicles into electric ones, known as "retrofitting".

From Barron's ● May 3, 2026