# acapnial

CEFR C2 · Adjective

Source: https://englishreference.com/word/acapnial
Updated: 2026-05-26

## Definition

describing a situation where there is no carbon dioxide in the air. This is a very technical word used in science and medicine.

For teachers: containing no carbon dioxide. Typically used in medical or physiological contexts to describe the absence of carbon dioxide in the air or blood.

## Examples

- The patient was breathing acapnial air during the experiment.
- In a controlled laboratory setting, the researchers monitored the subject's response to breathing acapnial gas to study lung function.
- The acapnial environment created by the specialized mask allowed the divers to test their physiological limits without the usual buildup of carbon dioxide in their bloodstream.

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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.