# thermal

/ˈθɝməɫ/ (US) · /θˈɜːməl/ (UK)

Source: https://englishreference.com/word/thermal
Updated: 2026-06-19

## Senses

### 1. related to heat

adjective · CEFR B2 · Technical

relating to heat or temperature.

For teachers: pertaining to heat, temperature, or the movement of heat energy.

- The scientists measured the thermal energy produced by the chemical reaction.
- The spacecraft was equipped with a specialized shield to withstand the extreme thermal stress of atmospheric reentry.

### 2. keeping you warm

adjective · CEFR B2

designed to keep you warm by trapping heat, especially clothes.

For teachers: providing efficient thermal insulation to maintain body temperature in cold environments.

- You should wear thermal underwear if you are going skiing in the mountains.
- The hikers invested in high-quality thermal layers to ensure they remained warm during the overnight trek across the glacier.

### 3. rising air

noun · CEFR C1 · Technical

a column of rising warm air that birds and gliders use to stay high in the sky.

For teachers: a column of rising air in the lower atmosphere created by the uneven heating of the earth's surface.

- The eagle circled higher and higher as it caught a strong thermal.
- The glider pilot searched for a thermal over the sun-baked fields to gain enough altitude for the return journey.

### 4. heat-sensing camera

noun · CEFR C1 · Technical

a type of camera or sensor that sees heat instead of light.

For teachers: an infrared imaging device or sensor used to detect heat signatures, often in low-visibility conditions.

- The rescue team used a thermal to find the lost hikers in the dark woods.
- The surveillance drone was equipped with a high-resolution thermal to detect movement through the dense forest canopy at night.

## Examples

- The eagle circled higher by catching a thermal.
- The glider pilot searched for a strong thermal to gain enough altitude to cross the mountain range.
- Modern reconnaissance drones utilize high-resolution thermal imaging to detect heat signatures from vehicles and personnel through dense foliage or total darkness.

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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.