airtight

/ˈɛrˌtaɪt/
adjective
  1. Sealed so that no air can get in or out.
    • The container is airtight, so the cookies will stay fresh for weeks.
    • We need an airtight seal on the window to stop the draft.
    • The submarine's hatch must be airtight to keep water out.
  2. Having no weaknesses or flaws; impossible to disprove or argue against.
    • The detective built an airtight case against the suspect.
    • Her argument was airtight, leaving no room for doubt.
    • They signed an airtight contract that protected both parties.
Antonyms
What does "airtight" mean? | whatsthatwordmean | whatsthatwordmean