What does cryogenic mean?
Cryogenic describes conditions, equipment, or processes involving extremely low temperatures — conventionally below about −150 degrees Celsius (−238 degrees Fahrenheit). The word derives from the Greek roots 'kryos' (icy cold) and 'genes' (producing), so a cryogenic substance is literally one that produces cold. In practice, the adjective appears throughout science and industry: cryogenic freezers preserve biological samples, cryogenic fuels such as liquid hydrogen power rockets, and cryogenic liquids like liquid nitrogen are used to flash-freeze food and cool superconducting magnets. The related noun cryogenics names the branch of physics and engineering devoted to producing and using these frigid conditions. Although the term has a precise technical meaning, it is often applied more loosely to anything intensely cold. Its connotations are clinical and high-tech, evoking laboratories, spaceflight, and futuristic preservation rather than ordinary winter weather.
adjectiveRelating to the production and use of very low temperatures, typically below about −150 °C (−238 °F), especially for storing or processing substances such as liquefied gases. Also used more loosely to describe anything involving extreme cold.
- Relating to the branch of physics or engineering concerned with producing and applying very low temperatures.
- (Of a substance, container, or process) involving storage, transport, or use of materials at temperatures below about −150 °C.
"The samples were stored in a cryogenic freezer at minus 196 degrees Celsius."
"Engineers used cryogenic cooling to keep the rocket's liquid oxygen and hydrogen propellants in their fluid states."
"Biological specimens are preserved in cryogenic vats until they are needed for research."
The 'cryo' in cryogenic comes straight from the Greek word for icy cold — the same frosty root that gives us cryotherapy and even the ice-cream treat made with liquid nitrogen.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cryogenic
Cryogenic combines two Greek-derived elements: 'kryos', meaning icy cold or frost, and 'genes', meaning born of or producing. The word emerged in the late nineteenth century alongside the new science of low-temperature physics, as scientists first succeeded in liquefying gases such as oxygen and nitrogen. The same Greek root 'kryos' appears in other technical terms such as cryosphere (the frozen regions of the Earth) and cryotherapy (treatment using cold), making cryogenic part of a small but productive family of cold-related vocabulary.
Related word forms
How cryogenic is actually used
A technical term common in scientific and industrial contexts; it is also used loosely — and sometimes hyperbolically — to mean simply 'extremely cold', though purists reserve it for temperatures below roughly −150 °C. The adverb form is 'cryogenically'.
Easily confused with cryogenic
Cryogenic refers to engineered extremely low temperatures (below roughly −150 °C), while hypothermic describes a dangerously lowered body temperature in a living organism.