English Reference
adjective

watertight

adj.
US /ˈwɔtɝˌtaɪt/ UK /wˈɔːtətˌaɪt/ wa·ter·tight

  1. 01 B2 Upper Intermediate

    made so tightly that water cannot get in or out.

    constructed or sealed so tightly as to be impermeable to water.

    Simple

    Make sure the container is watertight before you put it in your bag.

    In context

    The engineers tested the hull to ensure it was completely watertight before the submarine's first deep-sea mission.

    waterproofsealedleakproof
  2. 02 C1 Advanced Formal

    so well planned or explained that no one can find a mistake or defeat it.

    impossible to defeat, evade, or nullify; used of arguments, plans, or legal cases.

    Simple

    The police had a watertight case against the thief.

    In context

    The legal team spent months building a watertight argument to ensure the contract could not be challenged in court.

    Usage

    Often collocates with 'case', 'argument', 'alibi', or 'excuse'.


From water + tight. Compare Scots wattirticht (“watertight”), West Frisian wetterticht (“waterproof”), Dutch waterdicht (“waterproof, watertight”), German wasserdicht (“watertight, waterproof”), Danish vandtæt (“watertight”), Swedish vattentät (“watertight, waterproof”).

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

This entry
Level B2 · Upper Intermediate
Frequency Occasional
Updated