What does diathermancy mean?
Diathermancy is a rare technical noun meaning the property of transmitting heat, particularly radiant heat. It is used when discussing how readily heat passes through a substance or material, often comparatively, as in references to high or low diathermancy. The word belongs to an older scientific vocabulary and is less common in modern general writing than expressions such as heat conductivity or thermal conductivity. Its meaning should not be confused with temperature: diathermancy concerns the passage of heat rather than how hot something is. In historical optics and physics, the term also referred to the ability of a body to transmit radiant heat. Although rarely encountered today, diathermancy remains useful in precise descriptions of thermal behavior, especially in technical, comparative, or historical contexts.
nounThe property of a material to allow heat to pass through it, especially radiant heat.
- The property of a substance or material to transmit heat, especially radiant heat.
"The glass was tested to determine its diathermancy under infrared radiation."
"The metal's high diathermancy allows heat to spread rapidly through the vessel."
"The early study compared the diathermancy of different substances under radiant heat."
The plural is grammatically possible but rare; the noun is normally used in the singular or as an uncountable property.
"The study compared the diathermancies of several transparent materials."
Diathermancy describes not how hot a material becomes, but how readily heat can pass through it.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does diathermancy come from?
The word emerged in 19th-century English scientific vocabulary from Greek dia-, meaning “through,” and thermē or thermos, meaning “heat,” together with the English noun-forming suffix -ancy. It developed alongside related forms such as diathermic and diathermal, which describe heat-transmitting materials. Its wider cognate family includes words such as hyperthermia and thermography, all built on the Greek root for heat.
How diathermancy is actually used
A rare, formal, and chiefly technical term found in physics, materials science, and historical scientific writing. It is uncommon in general prose.
Easily confused with diathermancy
Diathermancy is the noun naming the property of transmitting heat, whereas diathermic is the adjective describing a substance that permits heat to pass through it.