watertight

/ˈwɔtərˌtaɪt/
adjective
  1. Designed or made so that water cannot get in or out.
    • The submarine has watertight compartments to keep it safe underwater.
    • Make sure the lid is watertight before you put the container in the pool.
    • They sealed the boat's hull with a watertight coating.
  2. Carefully planned and impossible to argue against or find a flaw in; completely valid.
    • The lawyer presented a watertight case to the jury.
    • We need a watertight contract to avoid any future disputes.
    • She had a watertight alibi for the time of the crime.
Antonyms
What does "watertight" mean? | whatsthatwordmean | whatsthatwordmean