1. relating to or caused by heat
2. designed to retain body heat

1. a rising current of warm air
2. thermal underwear
Usage: informal

Examples

• The thermal energy from the sun heats the Earth’s surface.
• She wore thermal socks to keep her feet warm during the hike.
• The thermal imaging camera detected heat signatures in the building.
• Eagles use thermals to soar high without flapping their wings.
• He packed his thermals for the camping trip in the mountains.
• The thermal blanket helped retain the patient’s body heat.
• Gliders search for thermals to gain altitude efficiently.