# main

/ˈmeɪn/ (US) · /mˈeɪn/ (UK) · CEFR A1 · Noun

Source: https://englishreference.com/word/main
Updated: 2026-08-15

## Definition

the largest or most important pipe in a system that carries water, gas, or electricity to a building. If it breaks, the whole house or street might lose its supply.

For teachers: the principal pipe or conduit in a system for conveying water, gas, or electricity to a series of buildings or throughout a specific structure.

## Examples

- The water main burst and flooded the entire street.
- Construction workers accidentally hit a gas main while digging the foundation for the new apartment complex.
- Engineers recommended replacing the Victorian-era water mains with modern materials to prevent the frequent pressure drops that have plagued the downtown district for years.

## Usage notes

- Often used in the plural ('the mains') when referring to the general supply system of a house.

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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.