Origin: Latin suffix -tion
Radiation has 8 different meanings across 1 category:
energy that is radiated or transmitted in the form of rays or waves or particles
"The Geiger counter began clicking rapidly as it detected high levels of radiation leaking from the damaged reactor core."
the act of spreading outward from a central source
"The news of her success spread like radiation through the entire office, reaching every corner within minutes."
syndrome resulting from exposure to ionizing radiation (e.g., exposure to radioactive chemicals or to nuclear explosions); low doses cause diarrhea and nausea and vomiting and sometimes loss of hair; greater exposure can cause sterility and cataracts and some forms of cancer and other diseases; severe exposure can cause death within hours
"he was suffering from radiation"
the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay
"The Geiger counter clicked rapidly as it detected radiation from the abandoned uranium mine, confirming that the unstable atoms were undergoing nuclear decay."
the spread of a group of organisms into new habitats
"The invasive fire ants quickly expanded their range through radiation, now colonizing neighborhoods across three states."
a radial arrangement of nerve fibers connecting different parts of the brain
"The neuroanatomy textbook detailed how radiation refers to the fan-like spread of nerve fibers that link various regions within the cerebral cortex."
(medicine) the treatment of disease (especially cancer) by exposure to a radioactive substance
"After several rounds of chemotherapy, the doctors decided to begin radiation to target the remaining tumors in her lungs."
The shooting forth of anything from a point or surface, like diverging rays of light.
"The lighthouse beam cut through the fog as radiation swept across the dark ocean."
In plain English: Radiation is energy that travels through space as waves or tiny particles.
"The doctor warned that too much exposure to radiation could be harmful."
Usage: Radiation refers to energy emitted as waves or particles that travel outward in all directions from a source, such as sunlight or nuclear decay. Use this term specifically for the physical process of emission rather than general spreading or diffusion.
The word comes from the Latin radiatio, meaning a spreading out or emission. It entered English through French as an abstract noun derived from the verb to radiate.