airtight

adjective

air·​tight ˈer-ˌtīt 

1

: impermeable to air or nearly so

an airtight seal

2

a

: having no noticeable weakness, flaw, or loophole

an airtight argument

b

: permitting no opportunity for an opponent to score

an airtight defense

airtightness noun

Examples of airtight in a Sentence

Store the food in an airtight container.

The defendant had an airtight alibi.

Recent Examples on the Web

The neighbor’s sign, while biting, underscored an emerging reality in Arizona’s sizable Latter-day Saints community — that while church members are overwhelmingly Republican, there is some erosion in their traditionally airtight support for Republicans. —Faith E. Pinho, Los Angeles Times, 13 Oct. 2024

These passed our leak test, but our avocado browned quite a bit overnight, suggesting that these containers aren’t entirely airtight. —Lizzy Briskin, Peoplemag, 9 Sep. 2024

But the United States' employment verification scheme is hardly airtight. —Edward Alden, Foreign Affairs, 11 Feb. 2013

Their defense is hardly airtight, but the schedule — the full schedule, not just the conference lineup — is largely devoid of teams capable of slowing the Cowboys’ attack. —Jon Wilner, The Mercury News, 15 May 2024

Word History

First Known Use

1719, in the meaning defined at sense 1

Kids Definition

airtight

adjective

air·​tight -ˈtīt 

1

: so tightly sealed that no air can get in or out

an airtight container

2

: too strong or effective to fail or be defeated

an airtight argument