thermal
THUR-muhl
/ˈθɜːrməl/
Relating to, caused by, or storing heat; designed to retain heat.
As an adjective, thermal describes anything related to temperature or heat energy. As a noun, it can refer to a rising column of warm air used by gliders and birds to gain altitude.
The story behind the word. Thermal traces directly back to the ancient Greek word 'therme', meaning heat. This root also gave us 'thermometer' (heat measurer) and 'thermos' (heat retainer).
Word relationships
- caloric: Caloric is an archaic term relating to heat as a physical fluid, whereas thermal is the modern scientific term relating to heat energy.
- frigid: Frigid specifically describes extreme cold, whereas thermal relates to the scientific concept of heat energy regardless of temperature.
Commonly confused with
- thermic: Thermic is a less common synonym of thermal, used almost exclusively in specialized chemical or medical terms (e.g., thermic effect of food).
Word family
- thermally (adverb): In a thermal manner; with reference to heat.
- thermodynamics (noun): The science of heat and other forms of energy.
Collocations
- thermal energy
- thermal insulation
- thermal conductivity
- thermal imaging
Example sentences
- "The spacecraft was wrapped in multi-layer thermal insulation to protect it from solar radiation." Engineering material selection
- "She poured the hot coffee into a thermal flask to keep it warm during the long hike." Everyday consumer product description
Memory hook
Think of a 'thermos'—it keeps your soup hot because of its thermal properties. All about the heat.
When not to use
Do not confuse with 'caloric', which is an outdated term for heat fluid, or 'kinetic' when referring to motion alone without heat.
Fun facts
- Birds like eagles and hawks rarely flap their wings when soaring; instead, they hitch a ride on 'thermals'—invisible columns of rising warm air created by the sun heating the ground.
Related words
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