# airtight

/ˈɛɹˌtaɪt/ (US) · /ˈeətaɪt/ (UK) · CEFR B2 · Adjective

Source: https://englishreference.com/word/airtight
Updated: 2026-05-18

## Definition

describing a situation or plan that is so perfect that it cannot be changed or challenged. It can also describe something that is completely sealed so no air can get in or out.

For teachers: impermeable to air or gas; also used figuratively to describe a plan or argument that is logically sound and cannot be refuted.

## Examples

- The new plan is airtight and will work perfectly.
- The lawyer presented an airtight case, leaving the jury with no room to doubt the defendant's guilt.
- The building's windows are sealed with an airtight membrane to prevent heat loss during the winter months, significantly reducing the overall energy consumption of the structure.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.