air·tight 
/ˈeɚˌtaɪt/ adjective
/ˈeɚˌtaɪt/ adjective 1 : tightly sealed so that no air can get in or out
▪ Store the food in an airtight container. 2 : too strong or effective to fail or to be defeated
▪ an airtight argument ▪ The defendant had an airtight alibi.
▪ Store the food in an airtight container.
▪ an airtight argument ▪ The defendant had an airtight alibi.
