# retrofit

/ˈɹɛtɹoʊˌfɪt/ (US) · /ɹˌɛtɹəʊfˈɪt/ (UK)

Source: https://englishreference.com/word/retrofit
Updated: 2026-08-27

## Senses

### 1. to modernize a structure or machine

verb · CEFR C1 · Technical

to add new parts or technology to an old building or machine to make it work better.

For teachers: to supply a device or structure with new components or parts that were not available at the time of original construction.

- The city decided to retrofit the old library with solar panels and better windows.
- Engineers were hired to retrofit the aging bridge with seismic dampers to ensure it could withstand a major earthquake.

Usage: Often used in the context of environmental upgrades or safety improvements.

### 2. computing/software

verb · CEFR C1 · Technical

to add a new feature to an older version of a computer program.

For teachers: to retroactively supply a fix or feature to a previous version of a software product; synonymous with 'backport'.

- The developers had to retrofit the security patch into the older version of the app.
- While the new interface is exclusive to the current release, the team managed to retrofit the core security updates for legacy users.

Usage: Commonly used as a transitive verb where the feature is the object.

### 3. an update or new part

noun · CEFR C1 · Technical

a new part or set of changes added to an old machine or building.

For teachers: an instance of retrofitting or the specific components added during the process.

- The energy-saving retrofit cost the company thousands of dollars but saved money later.
- The building's recent retrofit included a complete overhaul of the HVAC system to meet modern efficiency standards.

## Examples

- 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.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.