airtight
adjectiveUK /ˈeə.taɪt/
US /ˈer.taɪt/
Closed so tightly that no air can get in or out.
She put the cookies in an airtight jar to keep them fresh.
OTHER MEANINGS
2. Having no weak points that can be criticized or attacked.
The lawyer built an airtight case against the thief.
3. Not allowing anything to escape or enter, such as a gas or liquid.
The submarine has an airtight door to keep the water out.
4. Very clear and impossible to misunderstand.
His airtight explanation left no room for doubt.