# sterile

/ˈstɛɹəɫ/ (US) · /stˈɛɹaɪl/ (UK)

Source: https://englishreference.com/word/sterile
Updated: 2026-08-08

## Senses

### 1. free from germs

adjective · CEFR B2 · Technical

completely clean and free from bacteria or other living things that could cause infection.

For teachers: free from all living or viable microorganisms; clinically clean.

- The surgeon made sure all the tools were sterile before the operation started.
- Maintaining a sterile environment in the operating theatre is paramount to preventing post-operative infections in vulnerable patients.

Usage: Often used to describe medical equipment, environments, or dressings.

### 2. unable to reproduce

adjective · CEFR B2

unable to have babies or produce seeds or fruit.

For teachers: biologically incapable of reproduction or procreation.

- Mules are sterile animals, meaning they cannot have offspring of their own.
- The hybrid plant was intentionally bred to be sterile, ensuring that it would not spread uncontrollably into the surrounding ecosystem.

### 3. unproductive or boring

adjective · CEFR C1 · Formal

lacking new ideas, excitement, or results.

For teachers: fruitless, uninspiring, or lacking in creative or emotional stimulation.

- The meeting was sterile and we didn't come up with any new plans.
- Critics argued that the architect's latest design was sterile, lacking the human warmth and character found in his earlier works.

### 4. secure area

adjective · CEFR C1 · Technical

an area, like in an airport, that is kept safe and free from dangerous objects.

For teachers: denoting a secure zone, particularly in aviation, that has been cleared of prohibited items via security screening.

- Once you pass through security, you are in the sterile area of the airport.
- Passengers must remain within the sterile concourse once they have cleared the primary security checkpoint to ensure the integrity of the flight.

### 5. untraceable weapons

adjective · CEFR C2 · American English · Technical

weapons that are made in another country and cannot be traced back to their source.

For teachers: referring to foreign-made weaponry or equipment that cannot be traced back to the supplying nation.

- The agents were issued sterile weapons for the secret mission.
- The intelligence agency provided the insurgents with sterile munitions to maintain plausible deniability regarding their involvement in the conflict.

## Examples

- The surgeon needs a sterile environment for the operation.
- The hospital room felt cold and sterile, with nothing on the white walls to make it feel welcoming.
- While the laboratory must remain sterile to prevent contamination of the samples, the researchers found the windowless office space equally sterile and difficult to work in for long hours.

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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.