sewer

sewer — noun

1. A pipe buried beneath the ground that takes waste water and sewage from houses a

1.nounB2
Definition

A pipe buried beneath the ground that takes waste water and sewage from houses and other buildings to a facility where the waste can be cleaned and safely disposed of.

Example

The city council approved funding to repair the old sewer system beneath the downtown area.

sewer system — common compound noun

Beatriz noticed a foul smell coming from the sewer grate outside her apartment.

Common collocations
  • sewer system
  • sewer pipe
  • blocked sewer
  • main sewer
  • sewer line
  • underground sewer
  • sewer network
Synonyms
  • drain

    A more general term; a drain carries rainwater or used water away, while a sewer specifically handles human waste as well.

  • waste pipe

    Focuses on the function of carrying waste; can refer to pipes inside a building as well as the main underground system.

  • culvert

    A tunnel that carries water under a road or railway, usually for storm water rather than sewage.

Usage Note

Often used in the plural form 'sewers' to refer to the entire pipe network of a town or city. Also commonly appears in compound nouns such as 'sewer system', 'sewer pipe', and 'sewer line'.

Common Mistakes

The kitchen sink sewer is blocked.
The kitchen sink drain is blocked.
A sewer is the main underground pipe system, not the pipe directly under a sink.

2. A channel at ground level, usually left uncovered, that carries sewage and dirty

2.nounB2
Definition

A channel at ground level, usually left uncovered, that carries sewage and dirty water from buildings away instead of through a buried pipe.

Example

In the old quarter, waste water runs through an open sewer beside the narrow streets.

open sewer — standard compound for this sense

The local authorities covered the open sewer to prevent children from falling in.

Common collocations
  • open sewer
  • concrete sewer
  • street sewer
Synonyms
  • drain

    A more general word for any channel that removes water; 'open drain' is also a common alternative for this sense.

  • gutter

    A channel at the edge of a road that carries away rainwater, but not usually intended for human waste.

  • channel

    A broader term for any long, narrow passage through which water flows.

Usage Note

This sense is typically used in the compound 'open sewer' to distinguish it from the underground pipe system. It is most common in descriptions of older or less developed areas where a covered drainage system has not been installed.

Word family

Synonym discussion

Sense: noun/1

A sewer is specifically designed to carry human waste and waste water away from buildings, usually through an underground pipe network connected to a treatment plant. A drain is a more general term — it can refer to any pipe or channel that carries water away, such as a kitchen sink drain or a street drain, but household drains typically do not handle human waste. A culvert is a tunnel-like structure that allows water to pass under a road or railway, and it usually carries storm water rather than sewage. A conduit is a broader, more technical term for any channel that conveys water or other fluids — it could be a pipe, a canal, or a tube. In everyday language, people say 'the drain is blocked' for a minor plumbing issue in the home, but 'the sewer is blocked' suggests a more serious problem involving the main waste pipe system. For example: 'The kitchen drain is clogged with food scraps' versus 'The city sent workers to unblock the main sewer.'

drain ↗culvertconduitwaste pipe

Common collocations

Nouns

  • sewer worker
  • sewer repair
  • sewer maintenance
  • sewer construction

Phrases

  • sewer system
  • sewer pipe
  • open sewer
  • blocked sewer
  • main sewer

Prepositions

  • into the sewer
  • down the sewer
  • through the sewer
  • from the sewer

Etymology

LatinVulgar LatinOld Northern FrenchMiddle EnglishEnglish

The word 'sewer' entered English from Old Northern French 'sewiere', meaning a channel that drains water from a pond. This came from Vulgar Latin 'exaquāria', a word for a drain, which was formed from the Latin prefix 'ex-' (out of) and 'aqua' (water). Over time, the meaning shifted from any drainage channel to the specific underground pipes used in modern sanitation systems.