RER
noun
RER is a noun meaning “A type of railway system that generally runs from suburbs or satellite towns into a city centre, with a central tunnel or overground corridor with…” (English Wiktionary, September 2026). It is spelled R-E-R, and it appears about once in every 4 million words in written English (wordfreq, 2021 data). The plural of RER is RERs.
What does RER mean?
noun
- 1
A type of railway system that generally runs from suburbs or satellite towns into a city centre, with a central tunnel or overground corridor with higher speeds and more widely spread stations than a subway or metro.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Forms of RER
- RERs plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
How common is RER?
RER appears about once in every 4 million words in written English, the 58,714th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
Where does RER come from?
From French RER, often reinterpreted as "Regional Express Rail".
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).