English Reference
noun

drainage

n.
US /ˈdɹeɪnədʒ/ UK /dɹˈeɪnɪdʒ/ drainage UK spelling drainages

  1. 01 B2 Upper Intermediate

    the way that water or other liquids flow away from a place.

    the process of liquid flowing out of or being removed from a specific area, either naturally or through human intervention.

    Simple

    The heavy rain caused problems because the soil had very poor drainage.

    In context

    The natural drainage of the valley was disrupted by the new housing development, leading to unexpected pooling in the lower fields.

    runoffseepageoutflow
  2. 02 B2 Upper Intermediate

    the pipes or ditches used to carry water away from a building or an area.

    the physical infrastructure, including pipes, conduits, and trenches, designed to facilitate the removal of waste water or rainwater.

    Simple

    The city is investing millions to improve the old drainage under the streets.

    In context

    Engineers discovered that the Victorian drainage was insufficient for the modern city's requirements, necessitating a complete overhaul of the subterranean network.

    sewerageplumbingdrainage system
  3. 03 C2 Proficiency Technical Science

    a type of wind that blows down a slope or mountain.

    a katabatic wind that carries high-density air from a higher elevation down a slope under the force of gravity.

    Simple

    The cold drainage from the mountains made the valley much chillier at night.

    In context

    Meteorologists monitored the nocturnal drainage of cold air into the basin, which frequently resulted in localized temperature inversions.

    katabatic wind

Usage drainage systems

Even a small, do-it-yourself green roof requires many layers to protect the structure from roots and provide drainage.

The Conversation· 12 Aug 2026

The drainage system had to empty the pool in less than 24 hours without leaving puddles.

The Conversation· 7 Aug 2026

From drain + -age.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Level B2 · Upper Intermediate
Frequency Frequent
Updated