# anaerobic

/ˌænɝˈoʊbɪk/ (US) · /ˌæneəɹˈəʊbɪk/ (UK) · CEFR C1 · Adjective

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

## Definition

describing a process or living thing that does not need oxygen to survive or work. You often hear this word when talking about bacteria or exercise.

For teachers: relating to or occurring in the absence of oxygen. Often describes biological processes or organisms that thrive in oxygen-deprived environments.

## Examples

- Some bacteria are anaerobic and live deep in the soil.
- The athlete performed anaerobic exercises to build muscle strength and improve her sprinting speed.
- In the absence of oxygen, the muscle cells switch to anaerobic respiration, a process that produces energy quickly but results in the accumulation of lactic acid.

---

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.