thermal

Everyday

1. Having to do with heat. tree →
2. Made to keep you warm, like thermal socks or a thermal vest. tree →
3. (noun) A rising current of warm air that birds and gliders use to go up. tree →
4. (noun, thermals) Warm underclothes worn in very cold weather. tree →

In the lessons

In science lessons, «thermal energy» is heat energy; «thermal insulators» (wool, plastic) keep heat in; a «thermal imaging camera» shows warm things. Geography: «thermal springs» are hot springs, as in Rotorua in New Zealand. Eagles soar on thermals. Phrases: «thermal energy», «thermal insulation», «thermal springs», «thermal underwear».

Examples

• Thermal energy flows from hot things to cold things. tree →
• Wool is a good thermal insulator. tree →
• Wear your thermals when you go skiing. tree →
• The eagle circled up on a thermal. tree →
• Rotorua has bubbling thermal pools. tree →
• Firefighters use thermal cameras to find people in smoke. tree →
• My thermal flask keeps soup hot all day. tree →

Note

From the Greek word for heat, like «thermometer». As a noun for underwear it is usually plural: «thermals». Trap: «thermal» is about heat, but «thermal clothes» are worn to keep warm, not to cool down.