# reactor

/ɹiˈæktɝ/ (US) · /ɹɪˈæktɐ/ (UK)

Source: https://englishreference.com/word/reactor
Updated: 2026-06-20

## Senses

### 1. nuclear energy

noun · CEFR B2

a large machine that uses nuclear energy to create heat and electricity.

For teachers: an apparatus in which a nuclear chain reaction is initiated, sustained, and controlled to generate heat or produce useful isotopes.

- The power plant has three reactors that provide electricity for the whole city.
- Engineers monitored the core temperature of the nuclear reactor to ensure the cooling systems were functioning within safety parameters.

### 2. chemical production

noun · CEFR C1 · Technical

a container used in a factory to hold and control chemical reactions.

For teachers: a vessel designed for carrying out a chemical reaction, often equipped with mechanisms for temperature and pressure control.

- The chemicals are mixed inside a large steel reactor to create the plastic.
- The industrial reactor was lined with glass to prevent the acidic reactants from corroding the outer steel shell during the synthesis process.

### 3. electrical component

noun · CEFR C2 · Technical

a part in an electrical system that resists changes in current.

For teachers: an electrical device, such as an inductor, used primarily to introduce reactance into a circuit.

- The technician replaced the faulty reactor in the power supply unit.
- Current-limiting reactors are installed in the substation to protect the electrical grid from the high currents generated during a short circuit.

### 4. a person who reacts

noun · CEFR C2 · Formal

someone who responds to a situation or a suggestion.

For teachers: an individual who responds to a specific stimulus, influence, or suggestion.

- He is a slow reactor and needs time to think before he answers.
- Psychological studies often categorise participants as either fast or slow reactors based on their immediate physiological responses to stress.

## Examples

- The power plant uses a nuclear reactor to generate electricity.
- Engineers monitored the pressure levels inside the chemical reactor to ensure the safety of the production line.
- The transition to sustainable energy has sparked renewed debate over the safety and efficiency of modular nuclear reactors compared to traditional large-scale facilities.

---

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.