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

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Etymology

Origin of retrofit

retro- + fit ¹

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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

The fourth was to retrofit mobile storage systems in the park’s museum storage facility.

From Los Angeles Times ● Oct. 2, 2026

The most disruptive part of the retrofit work was carried out first, and included the insulation of shared walls, flooring and the roof.

From BBC ● Aug. 21, 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

The same is true for giving employees workplace options: Perhaps three configurations for the retrofit, each with a clear rationale, gets employees input without turning it into a second job.

From The Wall Street Journal ● Jun. 14, 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

Most of Walmart’s supply-chain buildings were built in the 1980s and ’90s, so about 80% of its automation construction projects are retrofits.

From The Wall Street Journal ● Oct. 9, 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

There are industry divides over which bill allows more flexibility to comply with new mandates and whether airlines should be required to make potentially costly retrofits of cockpit systems.

From The Wall Street Journal ● Jun. 30, 2026

Others contend that retrofits should be considered a cost of doing business, given how owners are on the hook for things like replacing leaky roofs or upgrading old electrical panels.

From Los Angeles Times ● Nov. 23, 2024

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

Baeli estimates energy demand in her retrofitted house has gone down by 88%, giving her a yearly saving of nearly £750 on her bills.

From BBC ● Aug. 21, 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

Bratton retrofitted a city bus and turned it into a rolling station house, with its own fax machines, phones, holding pen, and fingerprinting facilities.

From "The Tipping Point" by Malcolm Gladwell

But when it comes to retrofitting older homes it can be complex due to having to find space for the equipment, which adds to installation costs.

From BBC ● Jul. 9, 2026

Jones noted that the state offers grants through the Earthquake Brace+Bolt program to partially cover the cost of retrofitting older single-family homes that can slide off their foundation in an earthquake.

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

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

It could spend a bundle retrofitting to comply, or lose a bundle in sales.

From The Wall Street Journal ● Apr. 30, 2026

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